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Résumé L'étude du comportement de défense du nid chezAtta laevigata permet de classer les 4 castes physiques d'individus stériles étudiés en deux groupes. Le premier groupe, constitué par les ouvrièresminor etmedia, rassemble des individus pouvant reconnaître avec précision des intrus de même espèce. Menacés et mordus, ces derniers sont alors mutilés ou transportés puis abandonnés par les fourmis résidentes aux frontières de leur territoire. Les ouvrièresmajor et les soldats, formant le second groupe, nécessitent quant à eux le marquage de l'ennemi par la phéromone d'alarme de leurs congénères pour pouvoir prendre part aux affrontements intraspécifiques avec efficacité. Les soldats se montrent en revanche très performants dans la défense du nid contre des envahisseurs appartenant à d'autres espèces, développant dans ce cas une agressivité supérieure à celle observée chez les ouvrières. L'âge de ces dernières ou le type de tâche qu'elles assument ne semble pas influencer leur comportement agonistique qui est comparable dans les deux castes temporelles de récolteuses et d'architectes.
Polyethism and nest-defense in the leaf-cutting ant Atta laevigata (Fr. Smith)
Summary The study of the nest-defense behavior inAtta laevigata makes out the four physical castes of sterile individuals studied in two groups.Minor andmedia workers (first group) are able to recognize precisely the intruders of the same species that they threat, bite and mutilate or carry outside the territorial limits of the nest. As formajor workers and soldiers (second group), they need their ennemy to be impregnated by the alarm pheromone of their nestmates before they can take part with efficiency in the intraspecific fights. Soldiers though appear to be quite performent in the nest-defense against invaders from other species, showing in this case an aggressiveness superior to the one observed amongst workers. Age, for these, or the sort of work they assume don't seem to interfere with the agonsitic behavior that can be observed in both architects and foragers temporal castes.
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Résumé D'après des élevages faits en Côte d'Ivoire, on décrit les premières étapes du développement pour les colonies deB. natalensis, en examinant particulièrement la construction du nid, la formation de la meule à champignon et des amas de sciure de bois.Le couple imaginal fondateur creuse une cavité souterraine (copularium) où il élève, sans prendre aucune nourriture, la première couvée. Les premiers petits ouvriers creusent alors des galeries ascendantes par où ils vont attaquer le bois à la surface du sol, à l'abri de galeries couvertes. Les premiers grands ouvriers apparaissent peu après.En une seule nuit, les ouvriers construisent, à l'intérieur du copularium, un habitacle régulier de forme ovoïde; la première meule à champignons, d'emblée fertile, est édifiée à l'intérieur de cet habitacle; la sciure de bois, réserve alimentaire, est amassée à l'extérieur.Les homologies sont établies entre les structures et cavités du jeune nid et celles de la termitière adulte.
Summary Among the breedings carried out on the Ivory Coast, we could describe the first stages of development in colonies ofB. natalensis especially, by observing their nest-building, the growth of the fungus bed and of the heaps of saw-dust.The imaginal founder couple dig an underground cavity (copularium) in which they tend the first brood without taking any food themselves. Then, the first small workers dig ascending passage-ways through which they go in order to eat into the wood on the surface of the ground in the shelter of covered passage-ways. The first big workers come out soon after.In one night, inside the copularium the workers construct an even egg-shaped dwelling-place; the first fungus bed, at once fertile, is erected inside this dwelling-place; the heaps of saw-dust used as food-reserves are laid outside.Homologies are drawn between the structures and cavities of a young nest and those of an adult termitarium.
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Résumé L'auteur, au moyen d'observations régulières dans une colonie digynique expérimentale deMyrmecina graminicola, prouve la présence d'un rapport de domination entre les deux femelles. L'agressivité de la femelle contre la est déterminée par la présence des larves et des ouvrières, mais les ouvrières ne participent nullement au choix ou à l'élimination de la reine surnuméraire, contrairement à ce qui avait été observé pour d'autres espèces.
Summary Regular observation of a digynic experimental colony ofMyrmecina graminicola showed the existence of a dominance order between the two females. The aggressive behaviour of female towards female depends on the presence of larvae and workers, but the latter do not take any part in the choice or elimination of the supernumerary queen as has already been observed for other species.

Riassunto L'autore, mediante osservazioni regolari in una colonia diginica sperimentale diMyrmecina graminicola, dimostra la presenza di un rapporto di dominazione trale due femmine. Il comportamento aggressivo della femmina nei confronti della è determinato dalla presenza delle larve e delle operaie, ma quest'ultime non partecipano minimamente alla scelta od all'eliminazione della regina soprannumeraria come era stato osservato in altre specie.
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To define the policy of our specialty with a consensus opinion, a questionnaire entitled “hybrid imaging” was sent to practicing nuclear medicine specialist physicians in France to obtain their opinion on the impact of this recent method in training and in the practice of nuclear medicine and on the relations between nuclear medicine specialists and other medical imaging specialists. This questionnaire, written by the office of the French Society of Nuclear Medicine (FSNM) and molecular imaging , was divided into four parts: Profile and experience in hybrid imaging, Relations with radiologists, Practice of CT scans with hybrid equipment, and the Future of the specialty and of training in nuclear medicine. The response rate was 60%, i.e. 374 completed questionnaires. Overall, the responses were uniform, whatever the respondent's experience, type and place of practice. Regular participation in hybrid imaging practice was the reply provided by the majority of respondents. In terms of relations with radiologists, such contacts existed in over 85% of cases and are considered as being of high quality in over 90% of cases. The vast majority of practitioners believe that hybrid imaging will become the standard. Opinions on the diagnostic use of CT scans are divided, as well as their interpretation by a radiologist, a nuclear medicine specialist or by both. In the opinion of the vast majority, hybrid equipment systems should be managed by nuclear medicine specialists. With regard to the future, nuclear medicine should remain an independent specialty with enhanced training in morphological imaging and a residency training program whose length should be increased to 5 years.  相似文献   

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《L'Anthropologie》2022,126(5):103074
The contribution of geology and geomorphology to architectural and technological study of the Atlantic coast of France megaliths is important and can be grouped into three main axes: to identify, interpret and dating. Identification refers to the sourcing of the megalithic materiel from 0 to 7 km, sometimes around 10 km, or even exceptionally around 30 km. It is never the entire supply that is affected by such long distances but only a few blocks, some of them are remarkably well staged in the megalithic architecture. Another contribution lies in a fresh look at the management of stone recognized through the modes of acquisition, transformation and use of the raw material. More particularly, the geomorphology associated with technological reading offers tools for recognizing ancient standing stones. In the context of the interpretation of funerary chambers, the two sciences open a large window on the modalities of the internal structuring of monuments. From the entrance to the end of the chamber, the organization and use of the space is documented, sometimes a symbolic coding emerges from the mineral walls. This symbolic coding is based on particular petrography, on surface conditions operating a subdivision of space, on granulometries and homogeneities of differentiated surfaces. The internal organization can also be marked with natural “patterns”, which refer to a completely new aspect of Neolithic thought. Finally, the last axis concerns relative dating, by recognizing forms of postmegalithic fossil erosion, geomorphology makes it possible to identify reused stelae. A very important tool in a current research context where an important episode of reuse of standing stones at the end of the middle Neolithic is anticipated in the construction of dolmens in the south of France.  相似文献   

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《Geobios》1986,19(2):207-229
The aim of this paper is to remark some morphologicaldifferences among the type-species of the genus ZurcheriaDouvillé and those species attributed to this genuf by Buckman & Brasil: the group of H. pugnaxVacek for which Schindewolf (1964) defined the genus Spinammatoceras, and the group of H. pertinaxVacek for which we propose Malladaites gen. nov.; new species of both genera are described. The stratigraphical range of these species is established in the Betic Cordillera.  相似文献   

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This work describes new species of ostracodes collected in the Middle and Upper Bathonian outcrops of the Grands-Causses, Southern France: Kirtonella vignesensis n. sp., Marslatourella bathonica n. sp., Micropneumatocythere montmejeaneansis n. sp., Praeschuleridea alzonensis n. sp., and illustrates the predominating species in the assemblages: Limnocythere larzacensis, Theriosynoecum aveyronensis et Fastigatocythere juglandiformis.Ostracode assemblages are characteristic of lacustrine to polyhaline and inner marine environments, and they vary according to changes in salinity, oxygen and trophic level.  相似文献   

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M Chamberland  R Boulé 《CMAJ》1990,143(8):725-730
We reviewed the available data on residents'' teaching role in the clinical setting to develop programs to improve their teaching skills. Articles published from 1966 to 1989 were identified through a computerized search of MEDLINE, and the bibliographies of identified papers were reviewed. Articles directly related to the topic were included and analysed. Taking into account their quality, we extracted data relevant to specific issues. Approximately 15% to 25% of an average work week was spent by residents in different teaching activities. Students acknowledged the importance of their contribution to clinical teaching. Residents benefitted from teaching by increasing their medical knowledge and promoting the development of important attitudes. Insufficient preparation for this task and the numerous practical problems faced by residents may explain their modest performance as teachers. Nevertheless, programs directed to residents might improve the quality of their teaching. We suggest some guidelines for the development of programs to improve their teaching skills and for future research.  相似文献   

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Three Middle Devonian tabulate coral species assigned to the genusRoemeria Milne-Edwards & Haime 1851 are described:R. infundibulifera (Goldfuss 1829), the type species of the genus, andR. minor SCHLÜTER 1885, both from the Rheinisches Schiefergebirge, and a new species,R. cubiniensis, from the Couvin area of Belgium. Their external and internal characters and microstructures are described in detail. The dominant morphological features they have in common are cerioid and locally fasciculate corallites and tabulae with an infundibuliform profile. The microstructure of the corallite walls is characterized by an hitherto undescribed association of an internal fibrous zone and a peripheral lamellar zone flanking a median plate made of small granules and larger elements of stellate form. The only micro-structural variation between the three species lies in the proportions of these components. Kurzfassung: Drei mittel-devonische tabulate Korallen-Arten werden zur GattungRoemeria Milne-Edwards & Haime 1851 gestellt und beschrieben: die Typus-ArtenR. infundibulifera (Goldfuss 1829) sowieR. minor SchlÜter 1885, beide aus dem Rheinischen Schiefergebirge, und eine neue Art,R. cubiniensis, aus der Umgebung von Couvin in Belgien. Äußere und innere gemeinsame Merkmale sind cerioide und nur stellenweise bündeiförmige Koralliten mit einem infundibuliformen Profil der Tabulae im Längsschnitt. Die MikroStruktur der Koralliten-Wände ist durch die bisher nicht beschriebene Verbindung einer internen fibrösen Zone mit einer peripheren Lamellenschicht gekennzeichnet, die um eine Median-Lamelle aus kleinen und großen Granulae mit Stern-Profil angeordnet sind. Nur das Größen-Verhältnis dieser Struktur-Elemente ist bei den drei beschriebenen Arten verschieden.  相似文献   

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Before the antibiotic’s era, the clinicians have shown the relation between epididymitis and Infertility. At the moment, venerial diseases are the principal cause of Epididymitis by the young man. The early diagnosis of the urethral infection (acute or not) associated with a suitable antibiotherapy will allow to protect the fertility.  相似文献   

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H. A. Guénin 《Genetica》1951,25(1):157-182
Sans résumé Avec 81 figures dans le texte  相似文献   

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