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La Foa, New Caledonia

Oxera pancheri Dubard, a name placed in synonymy under Oxera sulfurea Dubard in the revision of the genus in 1999 and 2004, is rehabilitated. Newly collected specimens, especially the first material ever with fruits, supports the recognition of this species, first described in 1906. Morphologically, O. pancheri differs from O. sulfurea by its racemiform inflorescences, its stamens and style slightly exserted and its velutinous fruits. Oxera pancheri seems morphologically closer (based on inflorescence type, shape and characteristics of the mericarps, juvenile foliage) to O. microcalyx Guillaumin than to O. sulfurea. Oxera pancheri is endemic to the southern part of New Caledonia's main island "Grande-Terre", growing on ultramafic substrates. The limited geographic distribution of this species and the threats to its remaining populations lead us to assign a provisional conservation status of Endangered using the IUCN Red List criteria. © Publications Scientifiques du Muséum national d'Histoire naturelle. Source

Losfeld G.,CNRS Center of Evolutionary and Functional Ecology | Escande V.,CNRS Center of Evolutionary and Functional Ecology | Escande V.,French Environment and Energy Management Agency | Jaffre T.,Institute Of Recherche Pour Le Developpement | And 2 more authors.

Herein, we explore the outlines of an innovative method based on the chemical recovery of metal-rich biomass produced in phytoextraction technologies. Taking advantage of the adaptive capacity of some New Caledonian plants to hyperaccumulate Ni2+ cations in their aerial parts, this technique is based on the direct use of metals derived from plants as " Lewis acid" catalysts in organic chemistry. Metallic cations contained in New Caledonian nickel hyperaccumulators are recovered through a simple cost-effective process and serve the preparation of heterogeneous catalysts used in synthetic transformations allowing access to molecules with high added-value. The design of all processes is in line with the principles of green chemistry; it is adapted to the new economic constraints; it offers a new relevant outlet for metal-rich biomass; and it represents an alternative to non-renewable mineral materials. © 2012 Elsevier Ltd. Source

Lebouvier N.,University of New Caledonia | Hue T.,Institute Agronomique neo Caledonien | Hnawia E.,University of New Caledonia | Lesaffre L.,University of New Caledonia | And 2 more authors.
Parasitology Research

The aim of the present study was to demonstrate acaricidal activity on the cattle tick Rhipicephalus (Boophilus) microplus of essential oils from endemic conifers of New Caledonia in the context of the development of natural alternatives. Acaricidal activity of essential oils extracted from resin and heartwood of five endemic conifers of New Caledonia (Araucaria columnaris, Agathis moorei, Agathis ovata, Callitris sulcata, and Neocallitropsis pancheri) was evaluated on 14- to 21-day-old Rhipicephalus microplus tick larvae using the Larval Packal Test bioassay. A first screening with 5 % dilute solution was carried out and the oils with 100 % of mortality at this rate were diluted until no activity was shown. The heartwood oils of the two Cupressaceae were the most active with LC50 value of 0.65 % for C. sulcata and 0.55 % for N. pancheri while resin oil of A. columnaris (LC50 = 1.62 %) was the most active of the Araucariaceae family. Negative control (ethanol) was not toxic to the larvae. The chemical composition of essential oil from resin of A. columnaris was analyzed by gas chromatography-mass spectrometry. The essential oil was characterized by high level of sesquiterpene hydrocarbons and oxygenated sesquiterpenes and was composed mainly of aromadendrene (23.1 %) and bicyclogermacrene (16.0 %). In order to compare different plant resources in a sustainable program of natural acaricide, an "essential oil efficiency EOE" can be measured as the ratio between the yield of extraction and LC50 value. This study shows that A. columnaris (EOE = 2.36) and N. pancheri (EOE = 3.51) could provide valuable and effective natural acaricides for control of the cattle tick R. microplus. © 2013 Springer-Verlag Berlin Heidelberg. Source

Daval N.,Cabinet Veterinaire du Regain | Marchal C.,Service des Laboratoires Officiels Veterinaires | Guillaumot L.,Institute Pasteur Of Nouvelle Caledonie | Hue T.,Institute Agronomique neo Caledonien | And 3 more authors.
Parasites and Vectors

Background: Canine leishmaniasis (CanL), a parasitic zoonotic disease caused by Leishmania infantum and usually transmitted by phlebotomine sandflies, has rarely been reported in Pacific islands, which have been regarded until now as leishmaniasis-free territory. Here, we report the first autochthonous CanL case in New Caledonia (south-western Pacific) and the investigations carried out 1) to determine how infection was introduced into and transmitted among these dogs and 2) to assess the risks to animal and public health. Methods: Extensive epidemiological and entomological investigations in and around the focus were carried out. Leishmaniasis infection was confirmed by histopathology, indirect fluorescent antibody test, real-time PCR, and culture. Parasite strain was typed by the isoenzymatic technique. Results: The survey revealed close contacts between the autochthonous dog and two infected bitches imported from Spain, but failed to find any possible vector or disease spreading to other animals or humans. L. infantum zymodeme MON-1, the most frequent type in the Mediterranean basin, was identified. Although transplacental and venereal transmissions could not be excluded, the evidence was in favour of non-vectorial, direct dog-to-dog transmission. Conclusions: This study corroborates the possibility of non-vectorial routes (transplacental, venereal, and direct dog-to-dog) of canine leishmaniasis transmission in New Caledonia and raises the debate of relevant test requirements and diagnostic sensitivity prior to importation of dogs in Leishmania-free regions. New leishmaniasis control measures and recommendations to avoid future CanL introduction on the island are discussed. © 2016 Daval et al. Source

Perez J.,Institute Pasteur Of Nouvelle Caledonie | Brescia F.,Institute Agronomique neo Caledonien | Becam J.,Institute Pasteur Of Nouvelle Caledonie | Mauron C.,Institute Pasteur Of Nouvelle Caledonie | Goarant C.,Institute Pasteur Of Nouvelle Caledonie
PLoS Neglected Tropical Diseases

Background: Widespread but particularly incident in the tropics, leptospirosis is transmitted to humans directly or indirectly by virtually any Mammal species. However, rodents are recognized as the most important reservoir. In endemic regions, seasonal outbreaks are observed during hot rainy periods. In such regions, hot spots can be evidenced, where leptospirosis is "hyper-endemic", its incidence reaching 500 annual cases per 100,000. A better knowledge of how rodent populations and their Leptospira prevalence respond to seasonal and meteorological fluctuations might help implement relevant control measures. Methodology/Principal Findings: In two tribes in New Caledonia with hyper-endemic leptospirosis, rodent abundance and Leptospira prevalence was studied twice a year, in hot and cool seasons for two consecutive years. Highly contrasted meteorological situations, particularly rainfall intensities, were noted between the two hot seasons studied. Our results show that during a hot and rainy period, both the rodent populations and their Leptospira carriage were higher. This pattern was more salient in commensal rodents than in the sylvatic rats. Conclusions/Significance: The dynamics of rodents and their Leptospira carriage changed during the survey, probably under the influence of meteorology. Rodents were both more numerous and more frequently carrying (therefore disseminating) leptospires during a hot rainy period, also corresponding to a flooding period with higher risks of human exposure to waters and watered soils. The outbreaks of leptospirosis in hyper-endemic areas could arise from meteorological conditions leading to both an increased risk of exposure of humans and an increased volume of the rodent reservoir. Rodent control measures would therefore be most effective during cool and dry seasons, when rodent populations and leptospirosis incidence are low. © 2011 Perez et al. Source

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