Identification des constituants de l'essence des aiguilles de Pinus pinaster

The chromatographic analysis of the volatile leaf oil of Pinus pinaster Ait. showed 42% of monoterpene hydrocarbons (α-pinene, camphene, β-pinene, myrcene, 3-carene, limonene, cis-ocimene, terpinolene, para-cymene, 35% of sesquiterpene hydrocarbons (cubebene, copaene, caryophyllene, humulene, germacrene D, α- and γ-muurolenes, δ- and γ-cadinenes) and 23% of oxygenated compounds including esters (linalyl, bornyl, geranyl, neryl and farnesyl acetates), alcohols (cis-hexenol, linalool, α-fenchol, trans-pinocarveol, terpinen-4-ol, α-terpineol, dihydrocarveol, guaiol, junenol and α-cadinol), one aldehyde (hexenal) and one ketone (piperitone). Three non terpenoid phenylethyl esters were also identified: phenylethyl isovalerate, methyl-2 burtyate and 3-3 dimethylacrylate. Some alcohols and mainly α-terpineol and linalool seemed to be formed during the steam distillation process, they were absent when the leaf oil was obtained by maceration of small portions of leaves in the usual solvents of terpenes.     

XTH acts at the microfibril-matrix interface during cell elongation

Sulphorhodamine-labelled oligosaccharides of xyloglucan are incorporated into the cell wall of Arabidopsis and tobacco roots, and of cultured Nicotiana tabacum cells by the transglucosylase (XET) action of XTHs. In the cell wall of diffusely growing cells, the subcellular pattern of XET action revealed a 'fibrillar' pattern, different from the xyloglucan localization. The fibrillar fluorescence pattern had no net orientation in spherical cultured cells. It changed to transverse to the long axis when the cells started to elongate, a feature mirroring the rearrangements of cortical microtubules and the accompanying cellulose deposition. Interference with the polymerization of microtubules and with cellulose deposition inhibited this strong and 'fibrillar'-organized XET-action, whereas interference with actin-polymerization only decreased the intensity of enzyme action. Epidermal cells of a mutant with reduced cellulose synthesis also had low XET action. Root hairs (tip-growing cells) exhibited high XET-action over all their length, but lacked the specific parallel pattern. In both diffuse- and tip-growing cell types extraction of the incorporated fluorescent xyloglucans by a xyloglucan-specific endoglucanase reduced the fluorescence, but the 'fibrillar' appearance in diffuse growing cells was not eliminated. These results show that XTHs act on the xyloglucans attached to cellulose microfibrils. After incorporation of the fluorescent oligosaccharides, the xyloglucans decorate the cellulose microfibrils and become inaccessible to hydrolytic enzymes.     

Influence of aging on glycosaminoglycans and small leucine-rich proteoglycans production by skin fibroblasts

Skin aging is characterised by a progressive deterioration of its functional properties, linked to alterations of dermal connective tissue. Whereas many studies have been devoted to collagen alterations during aging, the situation is less clear concerning glycosaminoglycans and proteoglycans. Particularly, the alterations of the expression of small leucine-rich proteoglycans (SLRPs), a family of proteoglycans strongly implicated in cell regulation, have never been studied.In the present study we measured glycosaminoglycans and small leucine-rich proteoglycans synthesis by skin fibroblasts from donors of 1 month to 83 years old. [³H]-glucosamine and [³⁵S]-sulfate incorporation did not show significant differences of sulfated GAG synthesis during aging. On the other hand, a significant positive correlation was found between hyaluronan secretion and donor’s age. Northern blot analysis of SLRPs mRNAs showed a significant negative correlation of lumican mRNA with donor’s age, whereas decorin and biglycan mRNAs were not significantly altered. Immunohistochemical study and quantitative image analysis confirmed a decreased lumican accumulation in aged human skin.Taken together, our results suggest that impairment of glycosaminoglycans and SLRPs synthesis might be involved in the functional alterations of aged skin.     

Benefits of rebuilding global marine fisheries outweigh costs

Global marine fisheries are currently underperforming, largely due to overfishing. An analysis of global databases finds that resource rent net of subsidies from rebuilt world fisheries could increase from the current negative US$13 billion to positive US$54 billion per year, resulting in a net gain of US$600 to US$1,400 billion in present value over fifty years after rebuilding. To realize this gain, governments need to implement a rebuilding program at a cost of about US$203 (US$130-US$292) billion in present value. We estimate that it would take just 12 years after rebuilding begins for the benefits to surpass the cost. Even without accounting for the potential boost to recreational fisheries, and ignoring ancillary and non-market values that would likely increase, the potential benefits of rebuilding global fisheries far outweigh the costs.     

Patterns and propensities in reproduction and growth of marine fishes

A number of strong regularities characterize certain very basic biological parameters in marine fishes. For example, the ovulated eggs of fish usually measure approximately 1 mm in diameter. The small, relatively uniform size of the eggs means that almost all fish larvae experience environmental variability at very similar scales, which itself establishes strong constraints for, and links between reproduction and recruitment. Additional constraints emerge from seawater being a poor medium for respiration, which establishes further linkages between growth and mortality. These constraints have produced strongly convergent features, and thence the patterns in reproduction and growth of marine fishes that are presented.     

Reactive oxygen and nitrogen species and glutathione: key players in the legume-Rhizobium symbiosis

Several reactive oxygen and nitrogen species (ROS/RNS) are continuously produced in plants as by-products of aerobic metabolism or in response to stresses. Depending on the nature of the ROS and RNS, some of them are highly toxic and rapidly detoxified by various cellular enzymatic and non-enzymatic mechanisms. Whereas plants have many mechanisms with which to combat increased ROS/RNS levels produced during stress conditions, under other circumstances plants appear to generate ROS/RNS as signalling molecules to control various processes encompassing the whole lifespan of the plant such as normal growth and development stages. This review aims to summarize recent studies highlighting the involvement of ROS/RNS, as well as the low molecular weight thiols, glutathione and homoglutathione, during the symbiosis between rhizobia and leguminous plants. This compatible interaction initiated by a molecular dialogue between the plant and bacterial partners, leads to the formation of a novel root organ capable of fixing atmospheric nitrogen under nitrogen-limiting conditions. On the one hand, ROS/RNS detection during the symbiotic process highlights the similarity of the early response to infection by pathogenic and symbiotic bacteria, addressing the question as to which mechanism rhizobia use to counteract the plant defence response. Moreover, there is increasing evidence that ROS are needed to establish the symbiosis fully. On the other hand, GSH synthesis appears to be essential for proper development of the root nodules during the symbiotic interaction. Elucidating the mechanisms that control ROS/RNS signalling during symbiosis could therefore contribute in defining a powerful strategy to enhance the efficiency of the symbiotic interaction.     

Plattenepithelkarzinom des Schnabels – ein seltener maligner Tumor bei Pelikanen

Neoplasms appear very rare in pelicans. Few cases are described within the literature including 8 chondrosarcomas, 1 bile duct carcinoma, 1 bronchial carcinoma, 1 pheochromocytoma, 1 ganglioneuroma, and 1 case of a recurring squamous cell carcinoma. The present study describes the clinical and histopathological features of an epithelial neoplasm arising from the upper bill of a Dalmatian pelican (Pelecanus crispus) at Tierpark Berlin. The article deals with the surgery, the patients’ recovery and the pathology of such a neoplasm in detail.     

Endémisme insulaire et cleptoparasitisme chez les Lasioglossum Curtis 1833 (Hymenoptera : Apoidea : Halictidae) de Nouvelle-Calédonie

Huit espèces de Lasioglossum sont inventoriées de Nouvelle-Calédonie. Un nouveau sous-genre cleptoparasite endémique, avec une nouvelle espèce, Lasioglossum (Parachilalictus n. subg. ) neocaledonicum n. sp., est décrit. Les espèces endémiques suivantes du sous-genre Chilalictus sont nouvelles : Lasioglossum (Chilalictus) alticola n. sp., L. (C.) tchambae n. sp. et L. (C.) webbi n. sp. Une nouvelle sous-espèce, Lasioglossum (Chilalictus) polygoni austrocaledonicum n. ssp., est décrite de Nouvelle-Calédonie et d'Australie. Les espèces australiennes L. (Chilalictus) lanarium (Smith 1853) et L. (C.) instabilis (Cockerell 1914) sont découvertes pour la première fois en Nouvelle-Calédonie. Lasioglossum (Parasphecodes) sulthicum (Smith 1853) est la première espèce de ce sous-genre australien signalé en Nouvelle-Calédonie. L’émergence du parasitisme et la spéciation en condition insulaire font l'objet d'une discussion. Le cleptoparasitisme du nouveau sous-genre Parachilalictus n. subg. peut être établi en examinant un ensemble de caractères morphologiques convergents chez les groupes parasites de Halictidae dont les principaux sont la réduction de la brosse collectrice de pollen sur les pattes postérieures et l'aplatissement de la quille du labre. La forte ressemblance de Parachilalictus n. subg. avec les espèces de Chilalictus endémiques de Nouvelle-Calédonie et son absence en Australie suggère une spéciation locale et récente. Les deux nouvelles espèces endémiques décrites dans le sous-genre Chilalictus et dont Parachilalictus n. subg. pourrait avoir émergé ont une distribution montagnarde (L. alticola n. sp. , L. tchambae n. sp.). Dans le complexe L. polygoni (Cockerell 1929), la spéciation s'exprime par la variation de la densité et la force de la ponctuation. A basse altitude et le long de la côte ouest plus sèche, on trouve la sous-espèce typique polygoni. A des altitudes variant de 5 à 1150m, il existe clairement deux autres sous-espèces. La nouvelle sous-espèce austrocaledonica ne se trouve que dans la partie sud de l’île, en milieu ouvert de « maquis » tandis que la sous-espèce delobeli Pauly & Munzinger 2003 a une distribution plus étendue sur les massifs montagneux de la partie est, et a été rencontrée essentiellement le long de pistes forestières en forêt dense humide. Cette dernière sous-espèce habite aussi l'Australie.     

The new species Codium recurvatum from Tanzania

Codium recurvatum is described from material collected on a Tanzanian reef slope. The diminutive species is easily recognized by its unusual morphology, as its thallus consists of several dorsiventrally flattened lobes originating from a central holdfast and curving back towards the substratum. DNA barcodes (rbcL exon 1 and tufA) confirm the distinctness of the species and the phylogenetic placement of the new species is inferred from a concatenated alignment of rbcL and rps3–rpl16 sequences.