187 research outputs found

    Le référentiel taxonomique Florical et les caractéristiques de la flore vasculaire indigène de la Nouvelle-Calédonie

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    The taxonomic reference base Florical and characteristics of the native vascular flora of New Caledonia. The floristic inventory presented here comprises the evolving computerised database Florical (http://www.botanique.nc/herbier/florical). As of the date of publication, it lists all native vascular plant species (as well as infraspecific taxa) present in the territory of New Caledonia, whether validly published or in press, along with their basionym, organised according to the most recent classifications systems (APG III 2009 for the angiosperms, Smith et at [2006] for the ferns and lycophytes, and Mabberley [2009] for the gymnosperms), accompanied by their status (native or endemic) and the various vegetation types in which they occur. After a brief historical review of our knowledge of New Caledonian botany, the characteristics (richness, composition and endemism) of the different taxonomic groups (ferns and lycophytes, gymnosperms and then angiosperms -mono- and dicotyledons) are analyzed, followed by an assessment of the distribution of these groups among the vegetation types. The vascular flora of New Caledonia is characterised by its high level of richness (3371 species, including 3099 for the flowering plants alone), despite the absence or under-representation of some taxa that are abundantly represented elsewhere in the tropics, and especially by its remarkable distinctiveness (with endemism at the species level reaching 74,7%, and 77.8% for the flowering plants). The flora stands out by the presence of several relictual taxa and a high level of speciation among certain groups, despite the fact that the island was re-colonised relatively recently following the total submersion of its much older basement during the Paleocene and the Oligocene. Details of the measures taken to conserve this extraordinary natural heritage show that only 3.4% of the territory's total surface area is effectively protected. Despite the undeniable progress made in recent years by the authorities concerned, significant work remains to be done, especially in the northern Province

    Concerted changes in tropical forest structure and dynamics: evidence from 50 South American long-term plots

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    Several widespread changes in the ecology of old-growth tropical forests have recently been documented for the late twentieth century, in particular an increase in stem turnover (pan-tropical), and an increase in above-ground biomass (neotropical). Whether these changes are synchronous and whether changes in growth are also occurring is not known. We analysed stand-level changes within 50 long-term. monitoring plots from across South America spanning 1971-2002. We show that: (i) basal area (BA: sum of the cross-sectional areas of all trees in a plot) increased significantly over time (by 0.10 +/- 0.04 m(2) ha(-1) yr(-1), mean +/- 95% CI); as did both (ii) stand-level BA growth rates (sum of the increments of BA of surviving trees and BA of new trees that recruited into a plot); and (iii) stand-level BA mortality rates (sum of the cross-sectional areas of all trees that died in a plot). Similar patterns were observed on a per-stem basis: (i) stem density (number of stems per hectare; 1 hectare is 10(4) m(2)) increased significantly over time (0.94 +/- 0.63 stems ha(-1) yr(-1)); as did both (ii) stem recruitment rates; and (iii) stem mortality rates. In relative terms, the pools of BA and stem density increased by 0.38 +/- 0.15% and 0.18 +/- 0.12% yr(-1), respectively. The fluxes into and out of these pools-stand-level BA growth, stand-level BA mortality, stem recruitment and stem mortality rates-increased, in relative terms, by an order of magnitude more. The gain terms (BA growth, stem recruitment) consistently exceeded the loss terms (BA loss, stem mortality) throughout the period, suggesting that whatever process is driving these changes was already acting before the plot network was established. Large long-term increases in stand-level BA growth and simultaneous increases in stand BA and stem density imply a continent-wide increase in resource availability which is increasing net primary productivity and altering forest dynamics. Continent-wide changes in incoming solar radiation, and increases in atmospheric concentrations of CO2 and air temperatures may have increased resource supply over recent decades, thus causing accelerated growth and increased dynamism across the world's largest tract of tropical forest

    Pattern and process in Amazon tree turnover, 1976-2001

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    Previous work has shown that tree turnover, tree biomass and large liana densities have increased in mature tropical forest plots in the late twentieth century. These results point to a concerted shift in forest ecological processes that may already be having significant impacts on terrestrial carbon stocks, fluxes and biodiversity. However, the findings have proved controversial, partly because a rather limited number of permanent plots have been monitored for rather short periods. The aim of this paper is to characterize regional-scale patterns of 'tree turnover' (the rate with which trees die and recruit into a population) by using improved datasets now available for Amazonia that span the past 25 years. Specifically, we assess whether concerted changes in turnover are occurring, and if so whether they are general throughout the Amazon or restricted to one region or environmental zone. In addition, we ask whether they are driven by changes in recruitment, mortality or both. We find that: (i) trees 10 cm or more in diameter recruit and die twice as fast on the richer soils of southern and western Amazonia than on the poorer soils of eastern and central Amazonia; (ii) turnover rates have increased throughout Amazonia over the past two decades; (iii) mortality and recruitment rates have both increased significantly in every region and environmental zone, with the exception of mortality in eastern Amazonia; (iv) recruitment rates have consistently exceeded mortality rates; (v) absolute increases in recruitment and mortality rates are greatest in western Amazonian sites; and (vi) mortality appears to be lagging recruitment at regional scales. These spatial patterns and temporal trends are not caused by obvious artefacts in the data or the analyses. The trends cannot be directly driven by a mortality driver (such as increased drought or fragmentation-related death) because the biomass in these forests has simultaneously increased. Our findings therefore indicate that long-acting and widespread environmental changes are stimulating the growth and productivity of Amazon forests

    Homeostatic and pathogenic roles of GM3 ganglioside molecular species in TLR4 signaling in obesity

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    Innate immune signaling via TLR4 plays critical roles in pathogenesis of metabolic disorders, but the contribution of different lipid species to metabolic disorders and inflammatory diseases is less clear. GM3 ganglioside in human serum is composed of a variety of fatty acids, including long-chain (LCFA) and very-long-chain (VLCFA). Analysis of circulating levels of human serum GM3 species from patients at different stages of insulin resistance and chronic inflammation reveals that levels of VLCFA-GM3 increase significantly in metabolic disorders, while LCFA-GM3 serum levels decrease. Specific GM3 species also correlates with disease symptoms. VLCFA-GM3 levels increase in the adipose tissue of obese mice, and this is blocked in TLR4-mutant mice. In cultured monocytes, GM3 by itself has no effect on TLR4 activation; however, VLCFA-GM3 synergistically and selectively enhances TLR4 activation by LPS/HMGB1, while LCFA-GM3 and unsaturated VLCFA-GM3 suppresses TLR4 activation. GM3 interacts with the extracellular region of TLR4/MD2 complex to modulate dimerization/oligomerization. Ligand-molecular docking analysis supports that VLCFA-GM3 and LCFA-GM3 act as agonist and antagonist of TLR4 activity, respectively, by differentially binding to the hydrophobic pocket of MD2. Our findings suggest that VLCFA-GM3 is a risk factor for TLR4-mediated disease progression

    A Novel Mutation Involving the Initiation Codon of FGF3 in a Family Described with Complete Inner Ear Agenesis, Microtia and Major Microdontia (LAMM Syndrome)

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    LAMM syndrome (OMIM #610706) is a rare autosomal recessive syndrome characterized by the association of Michel aplasia, microdontia and malformation of the external ear. Different mutations in FGF3 gene were reported in several families presenting with this syndrome. Clinical features and genetic results observed in a family with LAMM syndrome are reported. The diagnosis of isolated Michel aplasia was initially made in this family composed of two affected children. Microtia and microdontia was recently evidenced in both patients suggesting the diagnosis of LAMM syndrome. New auditory and orodental iconography was performed permitting to describe the patients’ phenotype in depth and to report rare findings of LAMM syndrome. The sequencing of FGF3 gene identified a novel missense mutation (c.2T>G), substituting the first initiator methionine in arginine, in the fibroblast growth factor 3 (FGF3) at the homozygous state in both patients. LAMM syndrome was confirmed and appropriate genetic counseling performed

    The Presence–Absence Situation and Its Impact on the Assemblage Structure and Interspecific Relations of Pronophilina Butterflies in the Venezuelan Andes (Lepidoptera: Nymphalidae)

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    Assemblage structure and altitudinal patterns of Pronophilina, a species-rich group of Andean butterflies, are compared in El Baho and Monte Zerpa, two closely situated and ecologically similar Andean localities. Their faunas differ only by the absence of Pedaliodes ornata Grose-Smith in El Baho. There are, however, important structural differences between the two Pronophilina assemblages. Whereas there are five co-dominant species in Monte Zerpa, including P. ornata, Pedaliodes minabilis Pyrcz is the only dominant with more than half of all the individuals in the sample in El Baho. The absence of P. ornata in El Baho is investigated from historical, geographic, and ecological perspectives exploring the factors responsible for its possible extinction including climate change, mass dying out of host plants, and competitive exclusion. Although competitive exclusion between P. ornata and P. minabilis is a plausible mechanism, considered that their ecological niches overlap, which suggests a limiting influence on each other’s populations, the object of competition was not identified, and the reason of the absence of P. ornata in El Baho could not be established. The role of spatial interference related to imperfect sexual behavioral isolation is evaluated in maintaining the parapatric altitudinal distributions of three pairs of phenotypically similar and related species of Pedaliodes, Corades, and Lymanopoda

    Human immunodeficiency virus: 25 years of diagnostic and therapeutic strategies and their impact on hepatitis B and C virus

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    The human immunodeficiency virus (HIV) had spread unrecognized in the human population as sexually transmitted disease and was finally identified by its disease AIDS in 1981. Even after the isolation of the causative agent in 1983, the burden and death rate of AIDS accelerated worldwide especially in young people despite the confection of new drugs capable to inhibit virus replication since 1997. However, at least in industrialised countries, this trend could be reversed by the introduction of combination therapy strategies. The design of new drugs is on going; besides the inhibition of the three enzymes of HIV for replication and maturation (reverse transcriptase, integrase and protease), further drugs inhibits fusion of viral and cellular membranes and virus maturation. On the other hand, viral diagnostics had been considerably improved since the emergence of HIV. There was a need to identify infected people correctly, to follow up the course of immune reconstitution of patients by measuring viral load and CD4 cells, and to analyse drug escape mutations leading to drug resistance. Both the development of drugs and the refined diagnostics have been transferred to the treatment of patients infected with hepatitis B virus (HBV) and hepatitis C virus (HCV). This progress is not completed; there are beneficial aspects in the response of the scientific community to the HIV burden for the management of other viral diseases. These aspects are described in this contribution. Further aspects as handling a stigmatising disease, education of self-responsiveness within sexual relationships, and ways for confection of a protective vaccine are not covered

    Tepotinib treatment in patients with MET exon 14-skipping non-small cell lung cancer: long-term follow-up of the VISION phase 2 nonrandomized clinical trial

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    IMPORTANCE MET inhibitors have recently demonstrated clinical activity in patients with MET exon 14 (METex14)-skipping non-small cell lung cancer (NSCLC); however, data with longer follow-up and in larger populations are needed to further optimize therapeutic approaches.OBJECTIVE To assess the long-term efficacy and safety of tepotinib, a potent and highly selective MET inhibitor, in patients with METex14-skipping NSCLC in the VISION study.DESIGN, SETTING, AND PARTICIPANTS The VISION phase 2 nonrandomized clinical trial was a multicohort, open-label, multicenter study that enrolled patients with METex14-skipping advanced/metastatic NSCLC (cohorts A and C) from September 2016 to May 2021. Cohort C (>18 months' follow-up) was an independent cohort, designed to confirm findings from cohort A (>35 months' follow-up). Data cutoff was November 20, 2022.INTERVENTION Patients received tepotinib, 500mg (450mg active moiety), once daily.MAIN OUTCOMES AND MEASURES The primary end point was objective response by independent review committee (RECIST v1.1). Secondary end points included duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety.RESULTS Cohorts A and C included 313 patients (50.8% female, 33.9% Asian; median [range] age, 72 [41-94] years). The objective response rate (ORR) was 51.4%(95% CI, 45.8%-57.1%) with a median (m)DOR of 18.0 (95% CI, 12.4-46.4) months. In cohort C (n = 161), an ORR of 55.9%(95% CI, 47.9%-63.7%) with an mDOR of 20.8 (95% CI, 12.6-not estimable [NE]) months was reported across treatment lines, comparable to cohort A (n = 152). In treatment-naive patients (cohorts A and C; n = 164), ORR was 57.3%(95% CI, 49.4%-65.0%) and mDOR was 46.4 (95% CI, 13.8-NE) months. In previously treated patients (n = 149), ORR was 45.0% (95% CI, 36.8%-53.3%) and mDOR was 12.6 (95% CI, 9.5-18.5) months. Peripheral edema, the most common treatment-related adverse event, occurred in 210 patients (67.1%) (35 [11.2%] experienced grade >= 3 events).CONCLUSIONS AND RELEVANCE The findings from cohort C in this nonrandomized clinical trial supported the results from original cohort A. Overall, the long-term outcomes of VISION demonstrated robust and durable clinical activity following treatment with tepotinib, particularly in the treatment-naive setting, in the largest known clinical trial of patients with METex14-skipping NSCLC, supporting the global approvals of tepotinib and enabling clinicians to implement this therapeutic approach for such patients.Pathogenesis and treatment of chronic pulmonary disease

    Low incidence of SARS-CoV-2, risk factors of mortality and the course of illness in the French national cohort of dialysis patients

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