Ischemia time and liver transplantation, today

The aim of our study was to retrospectively evaluate the impact of ischemia time and other clinical factors on the development of liver allograft primary nonfunction (PNF). We enrolled 531 consecutive liver transplantations from 1998 to 2013, identifying 10 PNF (1.9%). PNF was found to be statistically related to 4 different variables: donor age >60 years (P =.01), female donor gender (P =.01), total ischemia time >10 hours (P =.03) and infusion of more than 30 fresh frozen plasma units during surgery (P =.02). The study focused on the clinical impact of total ischemia time. We grouped total ischemia time into 4 groups (Group 1: 647.5 hours; Group 2: between 7.5 and 10 hours; Group 3: between 10 and 12 hours; Group 4: >12 hours) and 2 groups (assigning a cut-off value of 10 hours): both these grouping systems significantly influenced the development of PNF and 1-year graft survival, with limited impact on long-term survival. We split total ischemia time in a "technical time," "hepatectomy time," and "warm ischemia time." Only the first 2 components were found to be statistically related to PNF development with P =.02 and P =.003, respectively. Further studies should focus on these aspects of PNF

Retrospective analysis: A validation procedure for the redesign of an environmental monitoring network

Monitoring networks are essential tools for the effective management of vulnerable or limited environmental resources. Cost and logistics constraints often suggest to reduce the number of monitoring sites while minimizing the loss of information determined by these changes. The problem can be rigorously addressed through the optimization of one or more objective functions that represent the managerial goals associated to the network. However, the use of objective functions is based on assumptions that in practical cases can be inaccurate. To overcome this problem, we have developed a retrospective analysis procedure that validates the degree of acceptability of the optimal reduced configuration at a local and global level. The procedure has been applied to a case study in Apulia, Italy, finding that the optimal reduced network was unable to recover the measured values of the monitored parameter of two discarded locations, making it unable to accomplish its monitoring goals

Transcriptome data from three endemic Myrtaceae species from New Caledonia displaying contrasting responses to myrtle rust (Austropuccinia psidii) [Data paper]

The myrtle rust disease, caused by the fungus Austropuccinia psidii, infects a wide range of host species within the Myrtaceae family worldwide. Since its first report in 2013 in New Caledonia, it was found on various types of native environments where Myrtaceae are the dominant or codominant species, as well as in several commercial nurseries. It is now considered as a significant threat to ecosystems biodiversity and Myrtaceae-related economy. The use of predictive molecular markers for resistance against myrtle rust is currently the most cost-effective and ecological approach to control the disease. Such an approach for neo Caledonian endemic Myrtaceae species was not possible because of the lack of genomic resources. The recent advancement in new generation sequencing technologies accompanied with relevant bioinformatics tools now provide new research opportunity for work in non-model organism at the transcriptomic level. The present study focuses on transcriptome analysis on three Myrtaceae species endemic to New Caledonia (Arillastrum gummiferum, Syzygium longifolium and Tristaniopsis glauca) that display contrasting responses to the pathogen (non-infected vs infected). Differential gene expression (DGE) and variant calling analysis were conducted on each species. We combined a dual approach by using 1) the annotated reference genome of a related Myrtaceae species (Eucalyptus grandis) and 2) a de novo transcriptomes of each species

Structure and genetic diversity of Ixora margaretae an endangered species. A baseline study for conservation and restoration of natural dry forest of New Caledonia

International audienceThe dry forests of New Caledonia are an excep- tional ecosystem because of their numerous endemic botan- ical species and their highly diversified fauna of insects, mollusks, reptiles and birds. Unfortunately, the area of the dry forests has been significantly reduced, mainly by human activities. Ecological, phenological and genetic analysis of Ixora margaretae, a symbolic species of the sclerophyll forest, has revealed contrasting traits among natural stands. The division of the natural range and then the separation of forest islands has greatly reduced the existing genetic vari- ability of this species. The genetic diversity is strongly structured in genetic clusters which correspond well to spe- cific ecotypes according to the environmental conditions and the forest types. Furthermore, genetic analysis of the reproductive and non-reproductive trees as well the half- sib families obtained by complete protection of mothertrees has revealed substantial genetic drift which has resulted in increased loss of allelic variability. The total consumption of seeds by mainly rats confirms the ob- served absence of natural regeneration. All these results show that measures taken to protect the stands of dry forests will not be enough to maintain sufficient genetic variability of I. margaretae populations in the long term. Assisted regeneration with control of the increase in var- iability will be necessary to maintain the biodiversity of the species. The results obtained for I. margaretae must be confirmed with other symbolic species in order to take the necessary measures for the effective preservation of the dry forests in New Caledoni

Mines et environnement en Nouvelle-Calédonie : les milieux sur substrats ultramafiques et leur restauration

International audienceLes substrats ultramafiques – ou terrains miniers – à l’origine du minerai de nickel, couvrent près du tiers de la Nouvelle-Calédonie, qui se place parmi les premiers producteurs de ce métal dans le monde. Mais l’exploitation minière à ciel ouvert nécessite d’importants décapages qui génèrent des problèmes d’érosion des sols, de dérèglement des débits hydriques, de pollution des cours d’eau et de perte de biodiversité.Ces substrats datant de 37 millions d’années portent une flore riche et originale, qui a largement contribué au classement de la Nouvelle-Calédonie comme un des principaux hotspots de biodiversité de la planète.Elle comprend environ 2 150 espèces végétales dont 82 % sont endémiques. Ces espèces sont en outre spécialisées, adaptées à des sols très pauvres en plusieurs éléments nutritifs et inversement très riches en magnésium, en nickel et en d’autres métaux. Ces milieux abritent également une faune d’une grande diversité.Ainsi la Nouvelle-Calédonie est confrontée à un double défi : celui d’exploiter une ressource minière considérable à même d’assurer au pays un développement économique important, et celui de protéger cette biodiversité exceptionnelle au nom des principes fondamentaux édictés mondialement. Dans ce contexte, la conservation des milieux abritant la plus grande part de la biodiversité, ainsi que la restauration des sites dégradés par l’exploitation minière s’imposent comme des nécessités incontournables.L’ouvrage décrit et illustre tout d’abord la variété des substrats ultramafiques, ainsi que la diversité des écosystèmes et de leurs composantes floristiques, zoologiques et microbiologiques. Le concept de restauration écologique des sites dégradés et les moyens nécessaires pour sa mise en oeuvre sont ensuite développés ; puis les modes de collecte, de germination, de conservation des semences et de production de plants d’espèces locales sont décrits, de même que les méthodes de revégétalisation. Enfin près de 100 espèces végétales utiles pour la restauration sont présentées.Cet ouvrage est destiné à un large public, allant des professionnels du secteur minier (sociétés minières, opérateurs de la revégétalisation, bureaux d’étude…) aux personnels des collectivités impliquées dans la gestion du patrimoine minier et biologique du pays, ainsi qu’aux scientifiques, enseignants, étudiants, et plus largement à toute personne intéressée par les terrains miniers et leur gestion environnementale