Un faciès sédimentaire anthropique original du mésolithique vauclusien : les terres noires à petits galets calcaires

Small alluvial gravels (some millimetres up to 40 mm) were selected and carried by mesolithic peoples to their settlement where they use them in fire related activities. These small gravels varies in size and quantity between their first appearance, at the end of the azilian period, and their scarceness in the final sauveterrian period. Within particular morphological context, their shape rapidly change and allows us to order occupational layers.     

Olfactory communication and counter-marking in brown brocket deer <Emphasis Type="Italic">Mazama gouazoubira</Emphasis>

Scent marking by defecation and urination in numerous small latrines may be related to resource defence in brown brocket deer (Mazama gouazoubira). Both males and females seem to be territorial, and both contribute to latrines where their ranges overlap. Latrines could thus potentially function as centres of information exchange and intrasexual competition. Counter-marking occurs when animals respond to invaders' marks with a greater number of marks. The objectives of this experimental study were to determine whether brown brocket deer distinguish dung of presumed invaders from their own and whether they counter-mark such faecal deposits. Two samples of dung (from unknown males or females and the experimental animal) were introduced near the latrines of 21 captive deer (13 males and eight females), and we observed their responses, including investigative (sniffing) and marking (urination and defecation) behaviours. Males investigated the introduced dung and their own latrine significantly more when the dung was from an unknown male than when it was their own. Females investigated unknown female dung significantly more than their own. Males counter-marked the introduced dung and their latrine significantly more when the dung was from an unknown male than when it was their own. Males marked with a shorter latency and at a greater frequency than females. Our data indicated that males counter-mark most intensively dung from male ‘intruders’ which may be related to intrasexual competition and resource defence. Females showed a non-significant tendency to counter-mark same sex intruders.     

A multilocus approach to assessing co-evolutionary relationships between <Emphasis Type="Italic">Steinernema</Emphasis> spp. (Nematoda: Steinernematidae) and their bacterial symbionts <Emphasis Type="Italic">Xenorhabdus</Emphasis> spp. (γ-Proteobacteria: Enterobacteriaceae)

Nematodes of the genus Steinernema Travassos, 1927 (Nematoda: Steinernematidae) and their associated bacteria, Xenorhabdus spp. (γ-Proteobacteria), are an emergent model of terrestrial animal-microbe symbiosis. Interest in this association initially arose out of their potential as biocontrol agents against insect pests, but, despite advances in their field application and the growing popularity of this model system, relatively little has been published to uncover the evolutionary facets of this beneficial partnership. This study adds to the body of knowledge regarding nematode-bacteria symbiosis by proposing a possible scenario for their historical association in the form of a cophylogenetic hypothesis. Topological and likelihood based testing methods were employed to reconstruct a history of association between 30 host-symbiont pairs and to gauge the level of similarity between their inferred phylogenetic patterns.     

Éléments d'une analyse sémiologique des gravures rupestres du Haut Atlas (vallée de l'Ourika, Maroc)

The semiological study of a set of rock engravings such as the one in the Haut Atlas would consist in studying the graphic elements within their context to determine their mutual relations, because such relations are meaningful. Some details could be signs to which we could attach a conventional meaning. But, being unable to identify these conventional signs by their meaning, we must look for similarities between the figures themselves. Indeed, the repetition of some relations will provide constitutive elements of the global meaning. Unfortunately, ignoring the relative positions of the figures, I can only give some indications about what such a study should entail. So, I focus on one hand on the attributes of the figures, which are, in any case, identity marks, and on the other hand, on the context of the figures, that is the graphics around the figure, in order to outline the likely semantic field and the actions, actual or symbolic, in which they are involved.     

Hétérogénéité de la Germination des Semences de Rumex crispus mise en Evidence et Essai d'Interprétation

Germination Heterogeneity of Rumex crispus L. seeds: Occurrence and Attempt at Interpretation. Rumex crispus L. seeds, harvested without taking into account localization of mother plants or seed position on single plants differ in their response to unfavourable conditions inductive of dormancy as a function of their weight. During induction, application of potassium or GA₃ prevents or reduces the entry into dormancy, suggesting that the observed heterogeneity is due to nutritional variations of the seeds in relation to their position on the mother plant.     

Alternative mating tactics of the gobiid fish <Emphasis Type="Italic">Bathygobius</Emphasis><Emphasis Type="Italic">fuscus</Emphasis>

The reproductive ecology of the gobiid fish Bathygobius fuscus was studied at Nobeoka, Miyazaki, Japan. Males of this species maintain small rock holes as a nest and females spawn an egg mass on the wall of the nest. The males employed two forms of mating tactic: nest holding and sneaking. A nest holder stayed in the nest and waited for a female to visit, whereas a sneaker intruded into a nest while a pair was engaged in reproduction. Males larger than 55 mm standard length were always nest holders; those of smaller size employed both tactics. As the larger males excluded the smaller males, the latter did not occupy a nest hole. With a decrease in the number of larger males, smaller males changed their mating tactic from sneaking to nest holding. The results suggest that male Bathygobius fuscus adopt a conditional strategy whereby they change their tactic depending on their social status. Electronic Publication     

Quorum sensing regulation in <Emphasis Type="Italic">Pseudomonas</Emphasis>

Expression of many bacterial genes is regulated in a cell density-dependent manner via small signal molecules known as autoinducers; this type of regulation is termed quorum sensing (QS). The QS systems that employ N-acyl-homoserine lactones (HSLs) are best un derstood in Gram-negative bacteria. QS regulates expression of various genes, including the genes responsible for the production of virulence factors, synthesis of exoenzymes and antibiotics, antagonistic properties of bacteria, etc. The QS systems of the genus Pseudomonas are linked to other global regulatory networks of the cell, and their functions are controlled by numerous additional regulatory factors. Such regulators and the QS systems together form an intricate multifactorial cascade regulatory network. The review considers the QS systems of several Pseudomonas species, their interaction with other regulatory systems, and their roles in the regulation of cell processes.     

Fitness aspects of transgenic <Emphasis Type="Italic">Aedes fluviatilis</Emphasis> mosquitoes expressing a <Emphasis Type="Italic">Plasmodium</Emphasis>-blocking molecule

Vector-born diseases cause millions of deaths every year globally. Alternatives for the control of diseases such as malaria and dengue fever are urgently needed and the use of transgenic mosquitoes that block parasite/virus is a sound strategy to be used within control programs. However, prior to use transgenic mosquitoes as control tools, it is important to study their fitness since different biological aspects might influence their ability to disseminate and compete with wild populations. We previously reported the construction of four transgenic Aedes fluviatilis mosquito lines expressing a Plasmodium- blocking molecule (mutated bee venom phospholipase A₂–mPLA₂). Presently we studied two aspects of their fitness: body size, that has been used as a fitness-related status, and the expression of major enzymes classes involved in the metabolism of xenobiotics, including insecticides. Body size analysis (recorded by geometric wing morphometrics) indicated that both male and female mosquitoes were larger than the non-transgenic counterparts, suggesting that this characteristic might have an impact on their overall fitness. By contrast, no significant difference in the activity of enzymes related to metabolic insecticide resistance was detected in transgenic mosquitoes. The implication on fitness advantage of these features, towards the implementation of this strategy, is further discussed.     

Breeding ecology of the gentoo penguin <Emphasis Type="Italic">Pygoscelis papua</Emphasis> at Kerguelen Archipelago

The gentoo penguin (Pygoscelis papua) is one of the most widespread penguin species and has been proven to be highly plastic in many aspects of its ecology. However, data from their sub-Antarctic range suggest an unexplained decline of their populations over the last 10–20 years, stressing the need for additional knowledge on their breeding ecology and demography. The present study provides insights into the breeding ecology of the gentoo penguin at a major breeding site, Kerguelen Archipelago, over three breeding seasons (1987, 2002 and 2003). Similarly to other northern populations, gentoo penguins breeding at Kerguelen exhibited winter laying, slow provisioning rate, slow growth rate associated with an extended rearing period and relatively low breeding success compared to southern populations. Our study also revealed interannual differences in the timing of laying and growth parameters as well as unusual sex differences in parental investment. Despite their high plasticity, there are indications that gentoo penguins at the northern edge of their range might work at the upper limit of their capacities. Sub-Antarctic populations would, therefore, be more sensitive to environmental changes than more southerly ones and need to be closely monitored.     

L’utilisation des reliefs pariétaux dans la réalisation des signes au Paléolithique supérieur

For a long time, the images of the Upper Paleolithic were represented in a way that emphasized their aesthetic qualities and ignored the specific characteristics of their natural supports. It is more damageable as the architecture of the decorated caves plays a real part, at different levels, in the elaboration of the parietal devices. As omnipresent elements of these devices, the signs play a determining part in this architecture. Analysing the links between the signs and their direct supports brings to light the various ways in which parietal devices can be used and also the integration and research for the volumes and frame. A study led inside the caves on a sample of 692 signs, distributed in the franco-cantabric paleolithic space, makes apparent the variety of the graphic choices left to the artists standing in front of the wall.     

Mégalithes et sociétés préhistoriques : concepts et terminologie

The restitution of the megalith’s technical manufacture, whith their assemblies lines and their sequences, enlarges the coast of the sens incluse in each Corsican monoliths. From the megalithics sites of Poghjaredda of Monte Rotondu (Sotta), Ciutulaghja (Appietu), and Presa (Altaghjè), some specifics activities area (pastoralism for example) or activities structured in the space (villages and tombs of middle Neolithic) interest this study. The contributions of many sciences permit to give an economic and social dimension to the choice of megalithics sites. Then, those choices are an aspect of the Neolithic process in Corsica, making part of sculpture and architecture. This study is conclued by a consideration on the actual worked stones’ terminology.     

<Superscript>1</Superscript>H, <Superscript>15</Superscript>N and <Superscript>13</Superscript>C assignment of the amyloidogenic protein medin using fast-pulsing NMR techniques

Thirty-one proteins are known to form extracellular fibrillar amyloid in humans. Molecular information about many of these proteins in their monomeric, intermediate or fibrillar form and how they aggregate and interact to form the insoluble fibrils is sparse. This is because amyloid proteins are notoriously difficult to study in their soluble forms, due to their inherent propensity to aggregate. Using recent developments in fast NMR techniques, band-selective excitation short transient and band-selective optimized flip-angle short-transient heteronuclear multiple quantum coherence we have been able to assign a 5 kDa full-length amyloidogenic protein called medin. Medin is the key protein component of the most common form of localised amyloid with a proposed role in aortic aneurysm and dissection. This assignment will now enable the study of the early interactions that could influence initiation and progression of medin aggregation. The chemical shifts have been deposited in the BioMagRes-Bank accession Nos. 25399 and 26576.     

Quallen an Nord‐ und Ostseeküste

Jellyfishes in the North and the Baltic Sea Jellyfish masses are not only a nuisance for bathers but have significant negative effects on marine ecosystems and economy. The causes of worldwide increasing jellyfish mass occurrences are not fully understood until today. Anthropogenic influences as submarine constructions, overfishing, eutrophication and climate warming are assumed as possible causes. Jellyfish and their relatives have fascinating capabilities and features, including their amazing regeneration potential, a high adaptability on changing environments and especially their weapons, the stinging capsules. Despite the simplicity of their nervous system jellyfish have astonishing perception senses.     

<Emphasis Type="Italic">Motilin</Emphasis> and <Emphasis Type="Italic">ghrelin</Emphasis> gene experienced episodic evolution during primitive placental mammal evolution

Motilin and ghrelin, members of a structure-function-related hormone family, play important roles in gastrointestinal function, regulation of energy homeostasis and growth hormone secretion. We observed episodic evolution in both of their prehormone gene sequences during primitive placental mammal evolution, during which most of the nonsynonymous changes result in radical substitution. Of note, a functional obestatin hormone might have only originated after this episodic evolution event. Early in placental mammal evolution, a series of biology complexities evolved. At the same time the motilin and ghrelin prehormone genes, which play important roles in several of these processes, experienced episodic evolution with dramatic changes in their coding sequences. These observations suggest that some of the lineage-specific physiological adaptations are due to episodic evolution of the motilin and ghrelin genes.     

Variability of esterase patterns in adult flies of the <Emphasis Type="Italic">saltans</Emphasis> species group of <Emphasis Type="Italic">Drosophila</Emphasis> (subgenus <Emphasis Type="Italic">Sophophora</Emphasis>)

Esterases are known for their involvement in several physiological processes and high degree of polymorphism, in many organisms. Such polymorphism has been used to characterize species and species groups and to study genetic changes occurred in their evolutionary history. In the present study, the esterase patterns of 19 strains from 10 species representative of the five subgroups of the saltans species group were analyzed using polyacrylamide gel electrophoresis and α- and β- naphthyl acetates as substrates. Fifty-one esterase bands were detected and classified as 31 α-esterases, 18 β-esterases and two α/β-esterases. On the basis of the inhibition patterns using Malathion and eserine sulfate, 34 bands were classified as carboxylesterases, 14 as acethylesterases and three as cholinesterases. Ten gene loci were tentatively established on the basis of data on band position in the gel, substrate preference and inhibition pattern. Twenty bands were species-specific, the remaining being shared by species from the same or different subgroups. Bands detected exclusively in males and bands with a different frequency or degree of expression between sexes were also detected. In the gels prepared for analysis of gene expression in the body parts (head, thorax and abdomen), the degree of expression of the β-esterases was higher in the thorax, while the α-esterases were expressed predominantly in the abdomen and thorax. A global view of the data available at present on the esterases of the species from the saltans group and their degree of polymorphism are presented, as well as the possibility of using some β-esterases, because of their characteristics in the gels, as markers for species identification.     

Current state of forage resources and feeding of reindeer (<Emphasis Type="Italic">Rangifer tarandus</Emphasis>) and musk oxen (<Emphasis Type="Italic">Ovibos moschatus</Emphasis>) in the arctic tundras of Wrangel Island

The species composition and aboveground biomass of plant and lichens and the composition of reindeer and musk ox diet in the arctic tundra of Wrangel Island were studied in 2004 to 2007. The above-ground phytomass in different areas of the island varied from 1105 to 2100 kg/ha. The composition of plants consumed by reindeer and musk oxen and their proportions in the diet were determined by standard micro-histological analysis of plant remains in their feces. The results showed that, either in winter or in summer, both species obviously preferred feeding on willows (Salicaceae), which comprised almost half of their diet. Moreover, their feeding was highly selective, especially with respect to sedges and rushes (Cyperaceae + Juncaceae) and legumes (Fabaceae). Although the contributions of these plant groups to the total aboveground phytomass were very small (less than 4 and 8%), their proportions in the diet reached 27 and 24%, respectively. Mosses were not a preferred forage: their proportion in the aboveground phytomass reached 40%, but that in the diets of both species was below 10% in summer and increased to 20% only in the winter diet of reindeer. At a high abundance of lichens (up to 20% of the aboveground phytomass), neither of the animals consumed them during the study period.     

Protoplast isolation and plant regeneration of different doubled haploid lines of cauliflower (<Emphasis Type="Italic">Brassica oleracea</Emphasis> var. <Emphasis Type="Italic">botrytis</Emphasis>)

Protoplasts were isolated from hypocotyls of 5-day-old seedlings of five doubled-haploid (DH) lines of cauliflower after enzymatic digestion in 0.1% macerozyme R-10 and 1.0% cellulose R-10. Shoot regeneration was achieved in four of the five DH lines. Protoplast yield and frequency of cell division and shoot regeneration varied among experiments and DH lines. Sequence-related amplified polymorphism (SRAP) analysis on all the regenerated plants of each DH line indicated that their genetic compositions were homologous with their mother plants, but few regenerated plants of DH lines no. 3 and 5 were detected with changes in ploidy levels.     

Genetic relatedness of <Emphasis Type="Italic">Trichoderma</Emphasis> isolates antagonistic against <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> f.sp. <Emphasis Type="Italic">dianthi</Emphasis> inflicting carnation wilt

Twenty-eight isolates of Trichoderma belonging to four different species were screened in vitro for their antagonistic ability against Fusarium oxysporum f.sp. dianthi causing carnation wilt. Three different levels of antagonism observed in dual plate assay were further confirmed by cell-free culture filtrate experiments. Isolates showing class I level of antagonism produced maximum lytic enzymes, chitinases and beta-1,3-glucanases. Genetic variability of 25 selected isolates was assessed by random amplified polymorphic DNA technique and the amplified products were correlated for their level of antagonism. Unweighed pair-group method with arithmetical averages cluster analysis revealed prominent inter-and intraspecific genetic variation among the isolates. Based on their genetic relationship, the isolates were mainly distributed into 3 major groups representing T. atroviride, T. pseudokoningii and T. harzianum, with 20-35% interspecific dissimilarity. However, the polymorphism shown by the isolates did not correlate to their level of antagonism.     

Dissociation and Reassociation of RTF and r-Determinants of the R-factor <Emphasis Type="Italic">NR1</Emphasis> in <Emphasis Type="Italic">Proteus mirabilis</Emphasis>

A model is proposed for the regulation of the number of copies of drug resistance genes per host cell by their dissociation and reassociation with transfer factors.