Modifications structurales des faisceaux vasculaires primaires de la tige de Cordyline indivisa (Agavaceae). 1. Analyse du patron de conversion

1987 ◽  
Vol 65 (2) ◽  
pp. 299-323 ◽  
Author(s):  
Sylvie Laliberté ◽  
Joachim Vieth
Keyword(s):  
Vascular Bundle ◽  
Distal Part ◽  
Proximal Part ◽  
Leaf Primordium ◽  
The Other ◽  
Leaf Trace ◽  
Lower Segment ◽  
Longitudinal Course ◽  
Definition Of ◽  
Two Stages

In Cordyline indivisa Kunth, the primary bundles change from the collateral type (distal part) to the amphivasal type (proximal part). This conversion is related to the pattern of the longitudinal course of the bundles. Ontogenically, this reflects the two stages in the construction of a vascular bundle: the formation of the lower segment, characterized by its indefinite distal end and its subsequent junction with a leaf primordium. That part of the lower segment, which is amphivasal when fully differentiated, is axial in nature; its differentiation proceeds independently of the junction with the primordium. The collateral and intermediate stages are characteristic of the junction strand and that part of the lower segment having a reoriented differentiation. Since their presence depends on the junction with the primordium and is under the influence of the latter, we relate them to the leaf trace. According to our view of vascularization, each "developmental unit" consists of an axial segment which extends in a leaf trace; new axial bundles may be emitted from one part or the other. Consequently, our definition of the leaf trace is opposed to the classical one which states that the leaf traces diverge at intervals from continuous axial bundles.

Ichnology and sedimentology of the “Argiles de Saïda” formation (Callovo-Oxfordian) of the Djebel Brame (Tiaret, Algeria)

2011 ◽  
Vol 182 (5) ◽  
pp. 417-425 ◽  
Author(s):  
Mohamed Bendella ◽  
Madani Benyoucef ◽  
Amine Cherif ◽  
Miloud Benhamou
Keyword(s):  
Debris Flow ◽  
Carbonate Rocks ◽  
Depositional Environment ◽  
Distal Part ◽  
Proximal Part ◽  
Trace Fossil ◽  
The Other ◽  
Fine Sediments ◽  
Sequential Organization ◽  
Basal Conglomerate

Abstract The focus of this note is an ichnological study of the “Argiles de Saïda” formation (Callovo-Oxfordian) in the Djebel Brame, a region representing the eastern extremity of the Tlemcenian domain and marked by rhythmic clay-sandstone sedimentation. From a lithostratigraphic viewpoint, the formation is composed of two units with a distinct sequential organization and trace fossil content. These deposits are characterized by weak to moderate bioturbation, eleven ichnogenera were found: Bergaueria, Chondrites, Diplichnites, Megagrapton, Neonereites, Nereites, Ophiomorpha, Palaeophycus, Rhizocorallium, Taenidium and Thalassinoides. The basal unit is mainly characterized by fine sediments organized into small turbiditic sequences. Most of the beds are around one centimeter thick except for the conglomerate layer, channelized by the debris flow. This layer is heterometric and polygenic. The soles of the beds are generally marked by flute and groove casts, proof of their erosion by the currents. Most of these siliciclastic beds are organized around a repetitive model, with a massive base and flat, parallel and/or wavy laminae at the summit. Occasionally there are also beds of complex ripple marks, fluid escape structures and convoluted laminae. This sedimentation was deposited in an offshore environment, below the storm action influence threshold. Most of ichnogenera are associated with episodic silica-clastic deposits. The disappearance of Bergaueria and Diplichnites ichnogenera corresponds to the period when the basal conglomerate layer was established, and constituted stressful conditions for the organisms responsible for the two traces. Conversely, above this level, the appearance of Taenidium and Thalassinoides seems to correspond to a colonization by opportunistic endobenthic organisms. The weak hydrodynamism of the depositional environment, as well as the associated trace fossils content, point to the distal part of the Cruziana ichnofacies. The other, coarser, unit is an alternation of greenish clays, carbonate rocks and occasionally slumped sandstone. It is dominated by storm sequences. The more proximal summit shows shoreface deposits marked by phases of emersion. As well as episodes of storms and oolitic deposition, there are, at the top of this unit, deposits from a reefal environment (“Subreefal Layer”). These are indicative of shallow depths. Observable trace fossil content points to the most proximal part of the Cruziana ichnofacies. The trace fossil distribution and sedimentology both reveal hitherto undisclosed bathymetric fluctuations. A major fluctuation, most likely due to tectonic instability, was recorded before the second sequence was established. These results call for the biostratigraphic and structural study of the “Argiles de Saïda” formation in the Tlemcenian domain.

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

scholarly journals Language Family Engineering with Product Lines of Multi-level Models

2021 ◽  
Author(s):  
Juan de Lara ◽  
Esther Guerra
Keyword(s):  
Software Engineering ◽  
Arbitrary Number ◽  
Formal Theory ◽  
The Other ◽  
Language Family ◽  
Top Down ◽  
Product Lines ◽  
Modelling Languages ◽  
Multi Level ◽  
Definition Of

AbstractModelling is an essential activity in software engineering. It typically involves two meta-levels: one includes meta-models that describe modelling languages, and the other contains models built by instantiating those meta-models. Multi-level modelling generalizes this approach by allowing models to span an arbitrary number of meta-levels. A scenario that profits from multi-level modelling is the definition of language families that can be specialized (e.g., for different domains) by successive refinements at subsequent meta-levels, hence promoting language reuse. This enables an open set of variability options given by all possible specializations of the language family. However, multi-level modelling lacks the ability to express closed variability regarding the availability of language primitives or the possibility to opt between alternative primitive realizations. This limits the reuse opportunities of a language family. To improve this situation, we propose a novel combination of product lines with multi-level modelling to cover both open and closed variability. Our proposal is backed by a formal theory that guarantees correctness, enables top-down and bottom-up language variability design, and is implemented atop the MetaDepth multi-level modelling tool.

scholarly journals Stratigraphic revision and reconstruction of the deep-sea fan of the Voirons Flysch (Voirons Nappe, Chablais Prealps)

2021 ◽  
Vol 114 (1) ◽  
Author(s):  
Jérémy Ragusa ◽  
Lina Maria Ospina-Ostios ◽  
Pascal Kindler ◽  
Mario Sartori
Keyword(s):  
Deep Sea ◽  
Distal Part ◽  
Accretionary Prism ◽  
Proximal Part ◽  
Late Eocene ◽  
Lithostratigraphic Units ◽  
Stratigraphic Record ◽  
Sea Fan ◽  
Stratigraphic Evolution ◽  
Depositional Setting

AbstractThe Voirons Flysch (Caron in Eclogae Geologicae Helvetiae 69:297–308, 1976), is a flysch sequence aggregated into the sedimentary accretionary prism of the Chablais and Swiss Prealps. Its palaeogeographic location is still debated (South Piemont or Valais realm). We herein present a stratigraphic revision of the westernmost unit of the former Gurnigel Nappe sensu Caron (Eclogae Geologicae Helvetiae 69:297–308, 1976): the Voirons Flysch. This flysch is subdivided into three lithostratigraphic units at the formation level (the Voirons Sandstone, the Vouan Conglomerate, the Boëge Marl), with an additional unit (Bruant Sandstone) of uncertain attribution, ranging from the early Eocene to probably the late Eocene. We further propose a new model of the depositional setting of the deep-sea of the Voirons Flysch based on palaeocurrent directions, the overall geometry and sedimentary features. This model depicts an eastward deflected deep-sea fan. The stratigraphic record of the proximal part of this fan is fairly complete in the Voirons area, whereas its most distal part is only represented by one small exposure of thinly bedded sandstones in the Fenalet quarry. The stratigraphic evolution of the Voirons Flysch shows two major disruptions of the detrital sedimentation at the transition between Voirons Sandstone—Vouan Conglomerate and Vouan Conglomerate—Boëge Marl. The cause of these disturbances has to be constrained in the framework of the palaeogeographic location of the Voirons Flysch.

Identity, Community and Belonging in gcc States

2018 ◽  
Vol 6 (4) ◽  
pp. 401-428
Author(s):  
Miriam R. Lowi
Keyword(s):  
Religious Affiliation ◽  
Protective Role ◽  
The Other ◽  
National Project ◽  
Scholarly Literature ◽  
National Community ◽  
The Difference ◽  
Definition Of

Studies of identity and belonging in Gulf monarchies tend to privilege tribal or religious affiliation, if not the protective role of the ruler as paterfamilias. I focus instead on the ubiquitous foreigner and explore ways in which s/he contributes to the definition of national community in contemporary gcc states. Building upon and moving beyond the scholarly literature on imported labor in the Gulf, I suggest that the different ‘categories’ of foreigners impact identity and the consolidation of a community of privilege, in keeping with the national project of ruling families. Furthermore, I argue that the ‘European,’ the non-gcc Arab, and the predominantly Asian (and increasingly African) laborer play similar, but also distinct roles in the delineation of national community: while they are differentially incorporated in ways that protect the ‘nation’ and appease the citizen-subject, varying degrees of marginality reflect Gulf society’s perceptions or aspirations of the difference between itself and ‘the other(s).’

scholarly journals Note on osmotic pressure

1914 ◽  
Vol 90 (615) ◽  
pp. 41-45
Keyword(s):  
Osmotic Pressure ◽  
Vapour Pressure ◽  
Numerical Data ◽  
The Other ◽  
Present Moment ◽  
Capillary Surface ◽  
Pure Solvent ◽  
Definition Of ◽  
Complete Account ◽  
Strict Definition

The vapour pressure theory regards osmotic pressure as the pressure required to produce equilibrium between the pure solvent and the solution. Pressure applied to a solution increases its internal vapour pressure. If the compressed solution be on one aide of a semi-permeable partition and the pure solvent on the other, there is osmotic equilibrium when the com-pression of the solution brings its vapour pressure to equality with that of the solvent. So long ago as 1894 Ramsay* found that with a partition of palladium, permeable to hydrogen but not to nitrogen, the hydrogen pressures on each side tended to equality, notwithstanding the presence of nitrogen under pressure on one side, which it might have been supposed would have resisted tin- transpiration of the hydrogen. The bearing of this experiment on the problem of osmotic pressure was recognised by van’t Hoff, who observes that "it is very instructive as regards the means by which osmotic pressure is produced." But it was not till 1908 that the vapour pressure theory of osmotic pressure was developed on a finu foundation by Calendar. He demonstrated, by the method of the "vapour sieve" piston, the proposition that “any two solutions in equilibrium through any kind of membrane or capillary surface must have the same vapour pressures in respect of each of their constituents which is capable of diffusing through their surface of separation"—a generalisation of great importance for the theory of solutions. Findlay, in his admirable monograph, gives a very complete account of the contending theories of osmotic pressure, a review of which leaves no doubt that at the present moment the vapour pressure theory stands without a serious rival Some confusion of ideas still arises from the want of adherence to a strict definition of osmotic pressure to which numerical data from experimental measurements should he reduced. Tire following definitions appear to be tire outcome of tire vapour pressure theory :— Definition I.—The vapour pressure of a solution is the pressure of the vapour with which it is in equilibrium when under pressure of its own vapour only.

A new muscle receptor organ in the antenna of the rock lobster Palinurus vulgaris : mechanical, muscular and proprioceptive organization of the two proximal joints J0 and J1

1983 ◽  
Vol 218 (1210) ◽  
pp. 95-110 ◽  
Keyword(s):  
Anterior Part ◽  
Proximal Part ◽  
The Other ◽  
Chordotonal Organ ◽  
Excitatory Postsynaptic Potentials ◽  
Rock Lobster ◽  
Postsynaptic Potentials ◽  
Muscle Receptor ◽  
Physiological Properties ◽  
Receptor Organ

(i) Following previous work on the morphological and physiological properties of the two distal joints (J2, J3) of the atenna of the rock lobster Palinurus vulgaris , the mechanical, muscular and proprioceptive organization of the two proximal joints between the antennal segments S1 and S2 (J1) and between S1 and the cephalothorax (J0) have now been studied. (ii) Articulated by two classical condyles, J1 moves in a mediolateral plane. One external rotator muscle (ER) and three internal rotator muscles (IR1, IR2, IR3) subserve its movements. J0 is articulated by two different systems: a classical ventrolateral condyle and a complex sliding system constituted by special cuticular structures on the dorsomedial side of the S1 segment and on the rostrum between the two antennae. J0 moves in the dorsoventral plane by means of a levator muscle (Lm) and a depressor muscle (Dm). A third muscle, the lateral tractor muscle (LTm), associated with J0 and lying obliquely across S1, may modulate the level of friction between the S1 segment and the rostrum. (iii) Proprioception in J1 is achieved by a muscle receptor organ AMCO-J1 (antennal myochordotonal organ for the J1 joint) associating a small accessory muscle (S1.am) located in the proximal part of the S1 segment and a chordotonal organ inserted proximally on the S1.am muscle and distally on the S2 segment. J0 proprioception is ensured by a simple chordotonal organ (CO-J0) located in the anterior part of the cephalothorax. (iv) The S1.am muscle is innervated by three motoneurons characterized by their very small diameters and inducing respectively tonic excitatory postsynaptic potentials, phasic excitatory postsynaptic potentials and inhibitory postsynaptic potentials. Anatomical and physiological observations suggest functional correlation between S1.am and IR1 motor innervation. (v) Mechanical and muscular organization of J0 and J1 are compared with that of the other joints of the antenna. The properties of the AMCO-J1 proprioceptor are discussed in relation to the other muscle receptor organs described in crustaceans.

Two Commentaries on Euclid's Definition of Proportional Magnitudes

1994 ◽  
Vol 4 (1) ◽  
pp. 181-198 ◽  
Author(s):  
Bijan Vahabzadeh
Keyword(s):  
18Th Century ◽  
The Other ◽  
Identical Manner ◽  
Definition Of

Euclid's definition of proportional magnitudes in the Fifth Book of the Elements gave rise to many commentaries. We examine closely two of these commentaries, one by al-Jayyānī (11th century) and the other by Saunderson (18th century). Both al-Jayyānī and Saunderson attempted to defend Euclid's definition by making explicit what Euclid had only implied. We show that the two authors explain Euclid's position in a virtually identical manner.

Correction to a definition of negation

1984 ◽  
Vol 49 (1) ◽  
pp. 47-50 ◽  
Author(s):  
Frederic B. Fitch
Keyword(s):  
Fixed Point ◽  
Personal Communication ◽  
The Other ◽  
Transfinite Induction ◽  
Original Form ◽  
Basic Logic ◽  
Double Negation ◽  
Original Letter ◽  
The Law ◽  
Definition Of

In [3] a definition of negation was presented for the system K′ of extended basic logic [1], but it has since been shown by Peter Päppinghaus (personal communication) that this definition fails to give rise to the law of double negation as I claimed it did. The purpose of this note is to revise this defective definition in such a way that it clearly does give rise to the law of double negation, as well as to the other negation rules of K′.Although Päppinghaus's original letter to me was dated September 19, 1972, the matter has remained unresolved all this time. Only recently have I seen that there is a simple way to correct the definition. I am of course very grateful to Päppinghaus for pointing out my error in claiming to be able to derive the rule of double negation from the original form of the definition.The corrected definition will, as before, use fixed-point operators to give the effect of the required kind of transfinite induction, but this time a double transfinite induction will be used, somewhat like the double transfinite induction used in [5] to define simultaneously the theorems and antitheorems of system CΓ.

Jainism in Danger? Temple entry and the rhetoric of religion and reform in post-colonial India

2020 ◽  
pp. 1-37
Author(s):  
MANISHA SETHI
Keyword(s):  
Twentieth Century ◽  
The State ◽  
The Other ◽  
Post Colonial ◽  
Colonial India ◽  
The Public ◽  
Public Debates ◽  
Definition Of ◽  
Open The Doors ◽  
The Relationship

Abstract A bitter debate broke out in the Digambar Jain community in the middle of the twentieth century following the passage of the Bombay Harijan Temple Entry Act in 1947, which continued until well after the promulgation of the Untouchability (Offences) Act 1955. These laws included Jains in the definition of ‘Hindu’, and thus threw open the doors of Jain temples to formerly Untouchable castes. In the eyes of its Jain opponents, this was a frontal and terrible assault on the integrity and sanctity of the Jain dharma. Those who called themselves reformists, on the other hand, insisted on the closeness between Jainism and Hinduism. Temple entry laws and the public debates over caste became occasions for the Jains not only to examine their distance—or closeness—to Hinduism, but also the relationship between their community and the state, which came to be imagined as predominantly Hindu. This article, by focusing on the Jains and this forgotten episode, hopes to illuminate the civilizational categories underlying state practices and the fraught relationship between nationalism and minorities.

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