Showing papers by "University of Grenoble published in 1984"
TL;DR: It is reported here that serially cultured adult papilla cells can induce the growth of hair when implanted into follicles which otherwise would not grow hairs.
Abstract: Mammalian hairs are formed by differentiation and keratinization of cells produced in the epidermal matrix (Figs 3, 4). Using the rodent vibrissa follicle as a model1, transplantation studies have shown that the dermal papilla, a discrete population of specialized fibroblasts, is of prime importance in the growth of hair2,3. Papillae induce hair growth when implanted into follicles4,5 and can interact with skin epidermis to form new hair follicles6. When grown in culture, papilla cells display singular morphological and behavioural characteristics compared with connective tissue cells from other skin sources7,8. We report here that serially cultured adult papilla cells can induce the growth of hair when implanted into follicles which otherwise would not grow hairs. This finding presents an opportunity to characterize properties distinguishing the papilla cell population from other skin fibroblasts, and, more specifically, those which control hair growth. The eventual application of this work to human hair replacement techniques can also be envisaged.
629 citations
TL;DR: In this article, a series of pine kraft lignins were prepared by a normal kraft cooks to different pulp yield levels and precipitation of the lignin from the black liquors by acidification and by successive acidification of the black liquor obtained from a flow-through cook.
Abstract: Two series of pine kraft lignins were prepared by a) normal kraft cooks to different pulp yield levels and precipitation of the lignins from the black liquors by acidification and b) by successive acidification of the black liquor obtained from a flow-through cook. All the lignins were extensively purified, subjected to elemental and methoxyl analysis and subsequently acetylated. Quantitative 13C-NMR analysis was carried out on acetylated samples and the results were combined with the results of phenolic group determination by means of aminolysis and with elemental analysis data. The various acetylated lignins were also subjected to analysis by size exclusion chromatography. All results are discussed with reference to known features of kraft cooking and of kraft lignins.
118 citations
TL;DR: Alkaline volcanic rocks, sometimes feldspathoid bearing, appear in variable stratigraphic positions within the Eocene of the middle part of Central Iran No magmatic zonation and no K2O enrichment in both time and space can be found in this volcanic sequence.
Abstract: Alkaline volcanic rocks, sometimes feldspathoid bearing, appear in variable stratigraphic positions within the Eocene of the middle part of Central Iran No magmatic zonation and no K2O enrichment in both time and space can be found in this volcanic sequence These facts together with other geochemical and geological features of the Iranian Eocene provinces do not agree with a volcanism related to a subduction zone model
93 citations
01 Mar 1984
TL;DR: In this article, a field of two-layer geostrophic turbulence driven internally by baroclinic instability is studied, and the dispersion of neutrally buoyant particles indicate an energy spectrum of the form E (k ) ∼ k −2.46±0.02, where k is the horizontal wavenumber, at scales less than that of energy injection.
Abstract: We report results of experiments with a field of two-layer geostrophic turbulence that is driven internally by baroclinic instability. Turbulence is first produced at a sharp, unstable density front and propagates horizontally until all of the stratified fluid contains quasi two-dimensional eddy motions. Continuing instability blocks the inverse energy cascade that is otherwise characteristic of two-dimensional turbulence, and causes the dominant length scale to be approximately constant. Ekman friction, however, causes the turbulence intensity to decay exponentially in time. Measurements of the dispersion of neutrally buoyant particles indicate an energy spectrum of the form E ( k ) ∼ k −2.46±0.02 , where k is the horizontal wavenumber, at scales less than that of energy injection. The experiments also have implications for horizontal mixing by mesoscale turbulence at density fronts. The spreading of the upper-layer fluid proceeds like t 1 2 over time scales much less than that for the exponential decay of fluid velocities, but on larger time scales mixing is reduced, and can be halted, by Ekman dissipation.
72 citations
01 Feb 1984
TL;DR: In this article, the β− decays of 103Nb and 105Nb have been studied at the fission product separators JOSEF and LOHENGRIN, and the lowest energy levels of these nuclei are consistent with the interpretation as members of rotational bands built on a 3/2+ [411] Nilsson state.
Abstract: Theβ
− decays of103Nb and105Nb have been studied at the fission product separators JOSEF and LOHENGRIN. Half-lives of (1.5±0.2) s and (2.95±0.06) s, respectively, have been determined for these decays. Fromγ singles andγ-γ coincidence measurements extended level schemes for103Mo and105Mo have been established for the first time. The lowest energy levels of these nuclei are consistent with the interpretation as members of rotational bands built on a 3/2+ [411] Nilsson state. Evidence is presented for the location of the 9/2+ [404] configuration.
35 citations
TL;DR: In this paper, the authors used simple molecular orbital theory to interpret the shortening of S ⋯· O distances in these compounds by σ-type interaction between the oxygen p and the sulphur p and d orbitals.
Abstract: 2-(2-Chlorobenzoylimino)-1,3-thiazolidine (I) and 3-benzoylimino-4-methyl-1,2,4-oxathiazane (II) present short intramolecular S ⋯· O contacts of 2.68 and 2.24 A, respectively. X-Ray and neutron diffraction at 122 K performed on (II), for comparison with (I), already studied, led to experimental charge density deformation maps which exhibit a strong peak around the sulphur atom. Using simple molecular orbital theory, it is possible to interpret the shortening of S ⋯· O distances in these compounds by σ-type interaction between the oxygen p and the sulphur p and d orbitals. The significant variation of the equilibrium S ⋯· O distance with the nature of the atom bonded to S is explained in terms of the strength of the coupling between X–S antibonding orbital and oxygen ione-pair orbitals.
34 citations
TL;DR: In this paper, the controllability of right-invariant control systems on Lie groups was studied and a generalization of these results in the general case of real semi-simple Lie groups were obtained.
33 citations
TL;DR: Using a light-driven system of protein synthesis it is shown that up to ten ribosomal proteins of the 30S and eight proteins ofThe 50S subunits are made in the chloroplast.
Abstract: Chloroplast ribosomal proteins from spinach have been prepared in the presence of a protease inhibitor and some modifications have been introduced to the previous characterization of the 50S subunits (Mache et al., MGG, 177, 333, 1980): 33 ribosomal proteins are detected instead of 34. No change has been observed for the 30S subunits.
30 citations
TL;DR: A comparison of ribosomal proteins from Escherichia coli and from chloroplasts of Spinach was made using two separate methods: electrophoretic migration and immunochemical cross-reaction between blotted E. coli ribosome proteins and chloroplast ribosomic subunits antisera.
Abstract: A comparison of ribosomal proteins from Escherichia coli and from chloroplasts of Spinach was made using two separate methods: electrophoretic migration and immunochemical cross-reaction between blotted E. coli ribosomal proteins and chloroplast ribosomal subunits antisera. It is shown that L2 from E. coli (E-12) and L4 from chloroplasts (CS-L4) comigrated and that E-L4 immunologically cross-reacted with the isolated CS-L4 antibody. Co-migration was observed for three additional couples of 50S ribosomal proteins. It is also shown that at least one 30S E. coli ribosomal protein immuno-cross reacted with a 30S chloroplast antiserum and that three couples of 30S ribosomal proteins comigrated.
29 citations
TL;DR: In this paper, a flow observation technique, using free surface floats, is presented which can be used to determine the distribution of the vertical component of vorticity in eddies shed from the cylinder.
Abstract: The characteristics of the free stream motion in a two meter wide by ten meter long rotating free surface flow facility are discussed. Experiments on the flow past a right circular cylinder whose axis is parallel to the rotation axis are presented for the following parameter ranges: 2,500≦Re≦37,500; Ro≧1.43; 0.33≦R/H≦1.67; and 0.05≦R/S≦0.25 where Re is the Reynolds number, Ro, the Rossby number, R/H, the cylinder aspect ratio and R/S, the channel blockage factor. A flow observation technique, using free surface floats, is presented which can be used to determine the distribution of the vertical component of vorticity in eddies shed from the cylinder. Using a case study approach this technique gives a quantitative verification that in rotating systems shed cyclones have a larger maximum relative vorticity than their anticyclonic counterparts. The surface float technique also is shown to be a good approach to investigating the decay of vortices in such a free surface flow facility. Using a constant...
27 citations
01 Sep 1984
TL;DR: The Rb-Sr and K-Ar dates obtained on whole-rock and fine fractions of the Caboclo, Bebedouro and Salitre Formations allowed the establishment of a chronostratigraphy for the sedimentary cover of the Sao Francisco Craton in the Northeast region of Brazil.
Abstract: The Rb-Sr and K-Ar dates obtained on whole-rock and fine fractions of the Caboclo, Bebedouro and Salitre Formations allowed the establishment of a chronostratigraphy for the sedimentary cover of the Sao Francisco Craton in the Northeast region of Brazil. For the Caboclo Formation, one compilation of the data shows that the formation suffered a late diagenetic event at 958 ± 38 Ma. The Bebedouro Formation is represented by an isotopic diagram of difficult interpretation. As the Rb-Sr and K-Ar dates are in agreement, an age between 930 to 900 Ma can be regarded as the age or late diagenesis. The Salitre Formation is a carbonate layer. Cationic resins have been used to dissolve the carbonate fraction, which is necessary in order to extract the clay fraction of such a rock. An age of 767 ± 18 Ma. was obtained and it was attributed to an early diagenesis. The dates define a chronology which is in conformity with the stratigraphic succession.
TL;DR: In this article, the authors extended the Turbulent Thermal Theory to allow for inertia effects on entrainment and consequently on the evolution of large density difference, axisymmetric and line thermals.
TL;DR: Negative binomial point processes as discussed by the authors are defined for which all finite-dimensional distributions associated with disjoint bounded Borel sets are negative binomial in the usual sense, and they are mathematically tractable models which can be used in many situations.
TL;DR: Although antibody was detected, the results were inconsistent and further purification of the antigens may eventually improve the methods of the micro-ELISA.
TL;DR: Tulving as mentioned in this paper showed that recognition performance is better than recall performance in the recognition task than in the recall task, and that a positir,c corrclation bctu'ecn recognition ancl re-call is shrxrnr.
Abstract: \Iodel of Retrieval as a new framework rvhich accounts for somc of the findings of recognition and recall. In his earlier paper (Tulving 1976), recognition and recall are assumed to differ onl.v rvitl'r respect to the nature of retrieval information. Hower.er, the earlier h1'pothesis has been revised, based or-r the direct comparison experirnent of recognition and recall. The Synergistic Ecphory Ilodel ofRetrieval is a frarnervork which explains the {indings of the direct comparisor-r experirnent. However, I will comrnent orr two points: (l) the possibilit,v of an altcrnative intcrprctation of the findings of the direct cornparison experirnent; and (2) the relation between the Svnergistic Ecphorv \'lodel of Retrieval and the classical strength theory of mernor,v. (1) Effects ofcopv cues and ofassociatir.e cues are found in the direct comparison experirnent of recognition and recall. The fcrnncr effccts ctrn bc obtaincd frorn thc fact that rccognition performance is better than recall per{orrriance, and that a positir,c corrclation bctu'ecn recognition ancl re,call is shrxrnr. The latter is cor-rcerned rvith a negative correlation betrveen lalsc positir.e responses to associiitive cues in recognition and correct respolrscs to thosc in recall. To explain these results, Tulvir-rg proposes the Sy'nergistic Ecphory \{odcl ofRctrieval, rvhich integrates ecphoric inforrna-tion and convcrsion tliresholds. It seems to me, horvever, that there are alternative explanations for the results of the direct comparison expcrimcnt. For example, one of thc possiblc cxplanations is that retrieval attributes in recognition and recall are different (Tajika 19130). Tajika conducted a factor analytic study to extract retrieval attributes in recogrrition and recall. Two factors emerged. One is a discriminative attribute whicl'r associates with perlorrnance on tests of the explicit targets', the other is an associativc attribute which is invoived in generating the targets irnplicitly. This rneans that recognition and recall difl-er not only with respect to the nature of the retrievtrl infbrrnation, but also with respcct to the retrieval attributes. The copy cues task Tulvirlg has used in thc direct comparison experiment can be associated rvith performance on tests of the explicit targets, regardless of recognition or recall. As a result, recognition and recall rvill show a similar pattern ofresponses in the copy cues task. Thesc results suggest a positive correlation between recognition and recall. Moreover, sulrjects process rctrieval information bctter from copy cues in the recognition task than in the recall task, because the task ma-'-draw lrore on the discrirnintrtive factor. Thcrefore, recognition per{crrrnance exceeds recall per'fbr-mance. Let …
TL;DR: Data show that specific alterations of the plastid mRNA pool do occur during the hormone-dependent chloroplast development as well as during the stationary phase of the culture cycle.
02 Jul 1984
TL;DR: The authors' MT systems integrate many advanced concepts from the fields of computer science, linguistics, and AI: specialized languages for linguistic programming based on production systems, complete linguistic programming environment, multilevel representations, organization of the lexicons around "lexical units", units of translation of the size of several paragraphs, possibility of using text-driven heuristic strategies.
Abstract: Our MT systems integrate many advanced concepts from the fields of computer science, linguistics, and AI: specialized languages for linguistic programming based on production systems, complete linguistic programming environment, multilevel representations, organization of the lexicons around "lexical units", units of translation of the size of several paragraphs, possibility of using text-driven heuristic strategies.We are now beginning to integrate new techniques: unified design of an "integrated" lexical data-base containing the lexicon in "natural" and "coded" form, use of the "static grammars" formalism as a specification language, addition of expert systems equipped with "extralinguistic" or "metalinguistic" knowledge, and design of a kind of structural metaeditor (driven by a static grammar) allowing the interactive construction of a document in the same way as syntactic editors are used for developing programs. We end the paper by mentioning some projects for long-term research.
TL;DR: In this paper, a computerized calculation comparing the apparent movement of the sun and the positions of the summits surrounding a given point, the duration of sunshine at this given point can be calculated for a chosen period of the year.
Abstract: In mountainous areas, the duration of sunny periods is an important but often unknown climatic parameter. The difference in amounts of sunshine between exposed and shade sides of mountains must be treated circumspectly, sometimes corrected, for it is dependent on the action of shadows and thus can sometimes reduce the amount of sunshine at a given spot quite considerably.
By using a computerized calculation comparing the apparent movement of the sun and the positions of the summits surrounding a given point, the duration of sunshine at this given point can be calculated for a chosen period of the year.
This same calculation repeated for frequent points within a same area is transferred to a grid. This grid can be used to draw maps of the potential amount of sunshine for that area at a precise date or between two given dates.
This kind of study can be a valuable aid, not only in research into the environment (the amount of insolation is a determining factor in the melting of snow or ice, the evaporation of lakes, the development of vegetation etc.) but also in the planning of an area (solar energy, exposition of buildings in an urban setting, research into sites for new tourist resorts etc.).
TL;DR: In this article, the authors discuss the different stresses which are applied to the aggregates during the laboratory testing procedures and the correlation between compressive or tensile strength and Los Angeles, Deval and Micro-Deval test results.
Abstract: La revue des essais d'acceptation des granulats, quant a leur qualite mecanique ou leur resistance aux agents atmospheriques, montre qu'il existe de tres nombreux essais empiriques en usage dans le monde mais pratiquement aucun n'est employe universellement. Dans cette communication il est passe en revue les divers modes de sollicitation imposes au granulat depuis sa production en carriere jusqu'a son emploi, en se referant notamment aux principes de la comminution. Cette etude, appliquee a divers types de roche (sedimentaire, metamorphique, ignee) dont les âges varient de l'Ordovicien au Miocene, montre en particulier que leur resistance en tension ou compression et leur perte de resistance due a la saturation en eau sont des indices significatifs de comportement si on les compare aux resultats des essais Los Angeles, Deval et Micro-Deval. Ainsi il est recommande d'appliquer les essais conventionnels de mecanique des roches aux granulats avant ou durant la mise en exploitation de carrieres. L'analyse de ces resultats, en parallele avec ceux des essais d'acceptation conventionnels, permettront d'ameliorer les previsions de leur comportement et eventuellement d'accepter des granulats juges marginaux et qui auraient ete refuses selon les normes actuelles. In this paper the different stresses which are applied to the aggregates during the laboratory testing procedures are discussed. Sedimentary, metamorphic and igneous rocks are considered and their age is from Ordovician to Miocene. Very good correlations are observed between compressive or tensile strength and Los Angeles, Deval and Micro-Deval test results; these correlations are explained by rock mechanics and comminution principles. Therefore, the authors suggest to realize systematically conventional rock mechanics tests on rock samples from the quarries to optimize the utilization of marginal aggregates.
02 Jul 1984
TL;DR: Three systems, ATLAS, THAM and VISULEX, which have been designed and implemented at GETA in collaboration with IFCI as tools operating around the ARIANE-78 system are presented.
Abstract: In this paper we will present three systems, ATLAS, THAM and VISULEX, which have been designed and implemented at GETA (Study Group for Machine Translation) in collaboration with IFCI (Institut de Formation et de Conseil en Informatique) as tools operating around the ARIANE-78 system. We will describe in turn the basic characteristics of each system, their possibilities, actual use, and performance.
TL;DR: In this article, the authors studied the s− decay of the fission product103Zr at LOHENGRIN and JOSEF and measured half-lives of (4.7±0.5) ns and (2.0± 0.6) ns of the levels at 164 and 248 keV are consistent with the Nilsson model estimates including pairing.
Abstract: The nucleus103Nb62 has been studied through the s− decay of the fission product103Zr at LOHENGRIN and JOSEF. The energies of the lowlying levels and the γ transitions indicate rotational bands based on the Nilsson proton configurations [422 5/2+] [303 5/2−] and [301 3/2−] at 0, 164 and 248 keV, respectively. The measured half-lives of (4.7±0.5) ns and (2.0±0.6) ns of the levels at 164 and 248 keV are consistent with the Nilsson-model estimates including pairing.
TL;DR: In this article, the bin-packing problem is studied from a probabilistic view, and it is shown that, when the sizes of the n elements to be packed are drawn independently from a probability distribution, then the minimum number of bins necessary for the packing of these n elements is asymptotically proportional to n in three cases.
TL;DR: The existence of a protein-kinase bound to chloroplast 70S ribosomes is also demonstrated, the enzyme is able to phosphorylate almost every chlorOPlast ribosomal protein.
TL;DR: Protein-RNA associations were studied by a method using proteins blotted on a nitrocellulose sheet and core particles obtained after treatment by LiCl of chloroplast 30S ribosomal subunit contained 3 proteins which probably play a part in the early steps of the assembly of the chloroblast 30s ribosome subunit.
Abstract: Protein-RNA associations were studied by a method using proteins blotted on a nitrocellulose sheet. This method was assayed with Escherichia Coli 30S ribosomal components. In stringent conditions (300 mM NaCl or 20 degrees C) only 9 E. coli ribosomal proteins strongly bound to the 16S rRNA: S4, S5, S7, S9, S12, S13, S14, S19, S20. 8 of these proteins have been previously found to bind independently to the 16S rRNA. The same method was applied to determine protein-RNA interactions in spinach chloroplast 30S ribosomal subunits. A set of only 7 proteins was bound to chloroplast rRNA in stringent conditions: chloroplast S6, S10, S11, S14, S15, S17 and S22. They also bound to E. coli 16S rRNA. This set includes 4 chloroplast-synthesized proteins: S6, S11, S15 and S22. The core particles obtained after treatment by LiCl of chloroplast 30S ribosomal subunit contained 3 proteins (S6, S10 and S14) which are included in the set of 7 binding proteins. This set of proteins probably play a part in the early steps of the assembly of the chloroplast 30S ribosomal subunit.
TL;DR: In this paper, several recursive relations concerning some statistics useful in identifying the order of autoregressive moving average are derived and the asymptotic behaviour of these statistics are studied.
Abstract: . Several recursive relations concerning some statistics useful in identifying the order of autoregressive moving average are derived and the asymptotic behaviour of these statistics are studied.
TL;DR: In this paper, a simple low-cost transparent furnace, well suited for vapor transport experiments, is described and its application to the growth of Mo 4 O 11 crystals is briefly reported.
TL;DR: A neutron powder diffraction study of 239PuD2.25 compound was performed at different temperatures, in order to determine the deuterium atoms positions and to study the occurrence of structural and magnetic phase transitions as mentioned in this paper.
TL;DR: In this paper, the authors provided some new and improved versions of an earlier procedure for the estimation of parameters for autoregressive moving average models suggested by the author (1979), and some numerical examples of the application of the procedure are also given.
Abstract: . This paper provides some new and improved versions of an earlier procedure for the estimation of parameters for autoregressive moving average models suggested by the author (1979). Some numerical examples of the application of the procedure are also given.
TL;DR: Polyethylene oxides are efficient phase transfer catalysts which promote the reduction of C�C, C�C bonds as well as aromatic substrates by the Na-k eutectic.
TL;DR: In amorphous GdAl spin glass, as in a number of other spin glasses, the susceptibility cusp first increases, then decreases in temperature with increasing field as discussed by the authors.
Abstract: In amorphous GdAl spin glass, as in a number of other spin glasses, the susceptibility cusp first increases, then decreases in temperature with increasing field. An explanation for this behavior is found in terms of a competition between the noncritical linear susceptibility and the critical nonlinear susceptibility.