56 research outputs found
The influence of weathering and soil organic matter on Zn isotopes in soils
Zinc is an essential micronutrient that is ultimately released during mineral weathering. In soils, organic matter plays a key role in influencing Zn partitioning and therefore on Zn biogeochemical cycling. Soil organic matter is partitioned between carbon that is more readily available for decomposition by microorganisms, and more stable carbon transiently preserved from decomposition. The role of the stable pool of soil organic matter on Zn biogeochemical cycling remains poorly understood. The pool of stable carbon is controlled by combination with mineral constituents or is material that is intrinsically resistant to decomposition. The Zn stable isotopes are fractionated by interactions between Zn and soil mineral and organic constituents. This study reports the Zn isotope composition of five Icelandic soil profiles derived from the same parent basalt and characterized by contrasting degrees of weathering and organic matter content (δ66Zn = + 0.10 ± 0.05 to + 0.35 ± 0.02‰), the distribution of reactive mineral constituents available to form associations with soil organic matter, and the amount of stable organic carbon. Throughout these soils, the δ66Zn isotope variations are little influenced by mineral constituents, but rather by soil organic matter content. These data suggest that a combination of organic matter accumulation and Zn loss by leaching is required to explain the observed decrease in Zn concentration in soils and lighter soil δ66Zn with increasing organic carbon content. These results suggest that the presence of stable organic carbon in soils provides a pool of light Zn, attributed to the Zn isotope signature of organic matter partially preserved from decomposition. Crucially, this stable organic carbon pool may also contribute to the formation of the light Zn isotope sink reported in organic-rich marine sediments, a key output required to explain the oceanic mass balance of Zn isotopes
Testing for the association of the KIAA1109/Tenr/IL2/IL21 gene region with rheumatoid arthritis in a European family-based study
INTRODUCTION:
A candidate gene approach, in a large case-control association study in the Dutch population, has shown that a 480 kb block on chromosome 4q27 encompassing KIAA1109/Tenr/IL2/IL21 genes is associated with rheumatoid arthritis. Compared with case-control association studies, family-based studies have the added advantage of controlling potential differences in population structure. Therefore, our aim was to test this association in populations of European origin by using a family-based approach.
METHODS:
A total of 1,302 West European white individuals from 434 trio families were genotyped for the rs4505848, rs11732095, rs6822844, rs4492018 and rs1398553 polymorphisms using the TaqMan Allelic discrimination assay (Applied Biosystems). The genetic association analyses for each SNP and haplotype were performed using the Transmission Disequilibrium Test and the genotype relative risk.
RESULTS:
We observed evidence for association of the heterozygous rs4505848-AG genotype with rheumatoid arthritis (P = 0.04); however, no significance was found after Bonferroni correction. In concordance with previous findings in the Dutch population, we observed a trend of undertransmission for the rs6822844-T allele and rs6822844-GT genotype to rheumatoid arthritis patients. We further investigated the five SNP haplotypes of the KIAA1109/Tenr/IL2/IL21 gene region. We observed, as described in the Dutch population, a nonsignificant undertransmission of the AATGG haplotype to rheumatoid arthritis patients.
CONCLUSIONS:
Using a family-based study, we have provided a trend for the association of the KIAA1109/Tenr/IL2/IL21 gene region with rheumatoid arthritis in populations of European descent. Nevertheless, we failed to replicate a significant association of this region in our rheumatoid arthritis family sample. Further investigation of this region, including detection and testing of all variants, is required to confirm rheumatoid arthritis association
Hunting indicators for community-led wildlife management in tropical Africa
Engaging local communities is pivotal for wildlife conservation beyond protected areas, aligning with the 30 × 30 target of the Kunming-Montreal Global Biodiversity Framework. We assessed the effectiveness of 33 offtake indicators, derived from hunter declarations, in monitoring the status and extent of degradation of hunted wildlife sourced from camera trap surveys and faunal composition analysis. The rodents:ungulates ratio in offtake and the mean body mass of total offtake emerged as practical and robust indicators of faunal degradation within hunting systems, with significant potential for broader application in similar tropical forest environments. Our findings provide a blueprint for managing and conserving natural resources in tropical regions through community-based initiatives. Involving local stakeholders ensures sustainable wildlife use and fosters ownership and responsibility. This study advances conservation efforts, bridging scientific rigor with community engagement for effective biodiversity preservation
Safety and efficacy of nintedanib as second-line therapy for patients with differentiated or medullary thyroid cancer progressing after first-line therapy. A randomized phase II study of the EORTC Endocrine Task Force (protocol 1209-EnTF)
BackgroundNintedanib is a triple-angiokinase inhibitor with potential activity in patients with advanced thyroid cancers, as radioiodine refractory differentiated thyroid cancer (RAIR DTC) and medullary thyroid cancer (MTC).DesignEORTC-1209 (NCT01788982) was a double-blind randomized (2:1 ratio) placebo-controlled phase II, multi-cohort study exploring the efficacy and safety of nintedanib in patients with progressive, locally advanced, and/or metastatic RAIR DTC and MTC. The primary endpoint was progression-free survival (PFS) in the per-protocol (PP) population for both cohorts. Secondary endpoints included response rate, duration of response, overall survival (OS), and safety.ResultsRAIR DTC cohort: Seventy out of the 75 planned patients with RAIR DTC (median age, 66 years; 39 women) who had progressed after one (76%) or two lines (24%) of previous systemic therapy were randomized to receive either nintedanib (N = 45) or placebo (N = 25). Of these, 69 patients started treatment and 56 met all inclusion criteria (PP). At data cutoff, the median duration of follow-up was 26.3 months in the nintedanib arm and 19.8 months in the placebo arm. In the PP population, the median PFS was 3.7 months [80% confidence interval (CI), 1.9–6.5] in the nintedanib arm and 2.9 months (80% CI, 2.0–5.6) in the placebo arm (HR = 0.65; 80% CI, 0.42–0.99; one-sided log-rank test P = 0.0947). No objective response was observed. The median OS was 29.6 months [80% CI, 15.2–not reached (NR)] in the nintedanib arm and not reached in the placebo arm. Grade 3–4 adverse events of any attribution occurred in 50% of patients receiving nintedanib and in 36% of patients receiving placebo. MTC cohort: Thirty-one out of the 67 planned patients with MTC (median age, 57 years; eight women) who had progressed after one (68%) or two (32%) lines of previous systemic therapy were randomized to receive either nintedanib (N = 22) or placebo (N = 9). Of these, 20 patients (15 in the nintedanib arm and five in the placebo arm) started treatment and met all inclusion criteria (PP). The median PFS was 7.0 months (80% CI, 1.9–8.7) in the nintedanib arm and 3.9 months (80% CI, 3.0–5.5) in the placebo arm (HR = 0.49; 95% CI, 0.16–1.53). No objective response was reported. The median OS was 16.4 months (80% CI, 12.1–24.9) in the nintedanib arm and 12.3 months (80% CI, 7.1–NR) in the placebo arm. Grade 3–4 adverse events of any attribution during the blinded period occurred in 59.1% of patients receiving nintedanib and in 33.3% of patients receiving placebo.ConclusionThis study did not suggest a clinically significant improvement of PFS with nintedanib over placebo in patients with pretreated RAIR DTC and MTC
Phylogeography and conservation genomics of the African lion (Panthera leo) at a continental and local scale based on mitochondrial and nuclear molecular markers
Presented at the 9th international wildlife ranching symposium: wildlife - the key to prosperity for rural communities, held on 12-16 September 2016 at Hotel Safari & the Safari Court, Windhoek, Namibia.The African lion (Panthera leo) is listed as "vulnerable" by the IUCN Red List, mainly threatened by indiscriminate killing, primarily as a result of retaliatory or pre-emptive killing to protect human life and livestock, and prey base depletion. Habitat loss and conversion has led to a number of subpopulations becoming small and isolated. With the weakened connectivity between the main strongholds, genetic drift and loss of genetic diversity could affect the genetic health of the species. In the present study, we investigated the evolutionary history of the species at different scales of time and space. A total of 182 samples were used, including a larger number of 77 samples from Tanzanian protected areas. The mitochondrial cytochrome b gene was sequenced and the specimens were genotyped for 11 microsatellites and more than 9,000 SNPs. The preliminary results indicate that the lion is structured into two lineages at the continental scale (West-Central vs South-Eastern), a pattern observed within many other large African savanna species displaying large distribution ranges. Pleistocene climatic oscillations and biogeographical barriers were proposed as the main factors to have driven the lineage sorting. The first results based on microsatellites highlighted that the Tanzanian population displayed good level of genetic diversities with no signs of inbreeding. Indication of isolation-by-distance nevertheless highlighted a potential future impact of fragmentation on the population genetic health. SNPs allowed to identify 3 populations of lions in Tanzania, geographically structured. Using various molecular markers, the present work will further explore the taxonomy and the evolutionary history of the African lion for bringing insights in its conservation requirements
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