Search results for " Root"
showing 10 items of 627 documents
On Sets of Words of Rank Two
2019
Given a (finite or infinite) subset X of the free monoid A∗ over a finite alphabet A, the rank of X is the minimal cardinality of a set F such that X⊆ F∗. A submonoid M generated by k elements of A∗ is k-maximal if there does not exist another submonoid generated by at most k words containing M. We call a set X⊆ A∗ primitive if it is the basis of a |X|-maximal submonoid. This extends the notion of primitive word: indeed, w is a primitive set if and only if w is a primitive word. By definition, for any set X, there exists a primitive set Y such that X⊆ Y∗. The set Y is therefore called a primitive root of X. As a main result, we prove that if a set has rank 2, then it has a unique primitive …
On the computation of intersection numbers for twisted cocycles
2020
Intersection numbers of twisted cocycles arise in mathematics in the field of algebraic geometry. Quite recently, they appeared in physics: Intersection numbers of twisted cocycles define a scalar product on the vector space of Feynman integrals. With this application, the practical and efficient computation of intersection numbers of twisted cocycles becomes a topic of interest. An existing algorithm for the computation of intersection numbers of twisted cocycles requires in intermediate steps the introduction of algebraic extensions (for example square roots), although the final result may be expressed without algebraic extensions. In this article I present an improvement of this algorith…
Phenotyping plant root and their interaction with soil micro-organisms
2014
International audience
Modeling the hydrological and mechanical effect of roots on shallow landslides
2016
This study proposes a new methodology for estimating the additional shear strength (or cohesion) exerted by vegetation roots on slope stability analysis within a coupled hydrological-stability model. The mechanical root cohesion is estimated within a Fiber Bundle Model framework that allows for the evaluation of the root strength as a function of stress-strain relationships of populations of fibers. The use of such model requires the knowledge of the root architecture. A branching topology model based on Leonardo's rule is developed, providing an estimation of the amount of roots and the distribution of diameters with depth. The proposed methodology has been implemented into an existing dis…
Unemployment Hysteresis in Transition Countries: Evidence using Stationarity Panel Tests with Breaks
2008
The authors test hysteresis versus the natural rate hypothesis in unemployment using panel data for transition countries covering the period 1991:1–2003:11.The advantages of the stationarity tests applied is that they exploit the cross-section variations of the series and, additionally, allow for a different number of endogenous breakpoints in the unemployment series. They do not impose independence on the panel members, so that the critical values are simulated based on their specific panel sizes and time periods. The findings stress the importance of accounting for exogenous shocks in the series and give support to the shifting natural-rate hypothesis of unemployment for all the countries…
Micropropagation ofAgeratum houstonianumby nodal segments
2017
Ageratum houstonianum is a bedding and flowering potted plant originated from Central America which is generally propagate by seed. In this report a preliminary in vitro technique for propagation of A. houstonianum was investigated. In vitro germinated seeds were used to establish aseptic shoot cultures of several clones. Seedling stem segments bearing 3-4 nodes were placed on Murashige and Skoog (MS) basal medium plus 20 g L-1 sucrose, 8.0 g L-1 Agar to induce axillary shoot development. Axillary shoots were subcultured into the same medium and nodal segments were sectioned and subcultured to increase the stock of shoot cultures. Shoot cultures of the selected clone AG14 were used to accom…
Dynamics of dry matter partitioning in young ‘Nocellara del Belice’ olive trees
2008
Dry matter partitioning of ‘Nocellara del Belice’ olive (Olea europaea L.) trees was assessed during one growing season. Four three-year-old potted trees from rooted cuttings trained to single-trunk free-canopy were destructively harvested at 30-day intervals during the growing season. The average dry matter increase was about 2 kg · year-1 per tree. Total plant dry weight increased linearly over the year, whereas root to shoot ratio followed a quadratic trend with its peak during winter. Dry matter of all canopy parts (trunk, branches, 1-year-old shoots, and leaves) increased linearly and leaves exhibited the fastest growth. Also fine roots accumulated dry matter over the year in a linear …
Thermoplastic Properties of Endodontic Gutta-percha: A Thermographic In Vitro Study
2014
Abstract Introduction Endodontic gutta-percha undergoes deformation at temperatures above 65°C. The temperature influence of heat carriers on gutta-percha cones was investigated in vitro. Methods Six single-rooted extracted teeth were embedded in resin and fixed. The root canals were prepared (ProFile; Dentsply Maillefer, Ballaiques, Switzerland) to different tapers and bisected. Thermographic images when heating the gutta-percha cones (Roeko, Langenau, Germany) with a heat carrier (ML .12; SybronEndo, Orange, CA) at 1 and 5 mm from the working length were made with an infrared thermal imaging camera (ThermaCam P640; Flir Systems, Taby, Sweden). The device temperature was preset at 200°C. T…
Intrapulpal temperature changes during root surface irradiation with an 809-nm GaAlAs laser
2002
The aim of this study was to explore, in vitro, whether the irradiation of human root surfaces with a diode laser might induce nonphysiologic intrapulpal temperature elevations and, therefore, jeopardize pulp vitality.The pulps were removed from human maxillary and mandibular incisors extracted for periodontal reasons. The root canals were enlarged to an apical size #60 file. The teeth were radiographed with standard dental films and a millimeter grid to determine root thickness. The thickness of dentin between the root surface and the pulp in the irradiation areas was 1, 2, and 3 mm. To determine intrapulpal temperature changes during laser irradiation, 0.5-mm K-type thermocouples were ins…
Coexpression of heat-evoked and capsaicin-evoked inward currents in acutely dissociated rat dorsal root ganglion neurons.
1997
Noxious heat is able to activate heat-sensitive nociceptors in the skin very rapidly, but little is known about the mechanisms by which heat is transduced. We used the whole-cell patch-clamp technique to study the effects of noxious heat and capsaicin on freshly dissociated rat dorsal root ganglion neurons in vitro. Using temperatures between 41 degrees C and 53 degrees C, 8 of 19 small neurons (phior = 30 microm) exhibited a heat-evoked inward current. All heat-sensitive neurons tested were also capsaicin-sensitive. Moreover, the heat response tended to be enhanced after capsaicin (360 +/- 150 pA versus 125 +/- 45 pA, P0.1, n = 7). Two of five heat-insensitive neurons were excited by capsa…