Our study reports the first data on mercury (Hg) isotope composition in marine European fish, for seven distinct populations of the European seabass, Dicentrarchus labrax. The use of δ202Hg and ...Δ199Hg values in SIBER enabled us to estimate Hg isotopic niches, successfully discriminating several populations. Recursive-partitioning analyses demonstrated the relevance of Hg stable isotopes as discriminating tools. Hg isotopic values also provided insight on Hg contamination sources for biota in coastal environment. The overall narrow range of δ202Hg around Europe was suggested to be related to a global atmospheric contamination while δ202Hg at some sites was linked either to background contamination, or with local contamination sources. Δ199Hg was related to Hg levels of fish but we also suggest a relation with ecological conditions. Throughout this study, results from the Black Sea population stood out, displaying a Hg cycling similar to fresh water lakes. Our findings bring out the possibility to use Hg isotopes in order to discriminate distinct populations, to explore the Hg cycle on a large scale (Europe) and to distinguish sites contaminated by global versus local Hg source. The interest of using Hg sable isotopes to investigate the whole European Hg cycle is clearly highlighted.
IFCT study administering 7.5 mg/kg Bevacizumab plus chemotherapy after chemotherapy induction did not improve outcomes in extensive SCLC patients.
This randomized phase II–III trial sought to ...evaluate the efficacy and safety of adding bevacizumab (Bev) following induction chemotherapy (CT) in extensive small-cell lung cancer (SCLC).
Enrolled SCLC patients received two induction cycles of CT. Responders were randomly assigned 1:1 to receive four additional cycles of CT alone or CT plus Bev (7.5 mg/kg), followed by single-agent Bev until progression or unacceptable toxicity. The primary end point was the percentage of patients for whom disease remained controlled (still in response) at the fourth cycle.
In total, 147 patients were enrolled. Partial response was observed in 103 patients, 74 of whom were eligible for Bev and randomly assigned to the CT alone group (n = 37) or the CT plus Bev group (n = 37). Response assessment at the end of the fourth cycle showed that disease control did not differ between the two groups (89.2% versus 91.9% of patients remaining responders in CT alone versus CT plus Bev, respectively; Fisher's exact test: P = 1.00). Progression-free survival (PFS) since randomization did not significantly differ, with a median PFS of 5.5 months 95% confidence interval (CI) 4.9% to 6.0% versus 5.3 months (95% CI 4.8% to 5.8%) in the CT alone and CT plus Bev groups, respectively hazard ratio (HR) for CT alone: 1.1; 95% CI 0.7% to 1.7%; unadjusted P = 0.82. Grade ≥2 hypertension and grade ≥3 thrombotic events were observed in 40% and 11% of patients, respectively, in the CT plus Bev group. Serum vascular endothelial growth factor (VEGF) and soluble VEGF receptor titrations failed to identify predictive biomarkers.
Administering 7.5 mg/kg Bev after induction did not improve outcome in extensive SCLC patients.
The relationship between soil aggregation at the silt-size scale, and soil organic C dynamics has scarcely been studied. In this work, we developed a fractionation protocol comprising complete ...dispersion of the fraction >
50 μm of the original soil sample, and subsequent size and density fraction of the <
50 μm fraction to isolate stable aggregates from the silt-size fraction of a silty cultivated temperate soil. This fraction also contained non-aggregated silt-size mineral particles and small amounts of non-occluded light organic particles. Slaking-resistant silt-size aggregates stored almost half of the total soil organic C (TOC) as organic matter bound to silt (8% TOC) and clay minerals (28% TOC) and as occluded organic particles (8% TOC). Clay mineralogy was related to aggregation at this scale, since aggregates were selectively formed from 2:1 clays, while quartz and kaolinite-like clays were preferentially found in the non-aggregated clay fraction. We conclude that stable microaggregates are formed within the silt-size fraction and store organic C both by adsorption and by entrapment of small organic particles. The turnover rate of organic carbon in such microstructures, their sensitivity to land use and cultivation practices, and their importance in different soil types remain to be determined.
Selection and plasticity are two mechanisms that allow the adaptation of a population to a changing environment. Interaction between these nonexclusive mechanisms must be considered if we are to ...understand population survival. This review discusses the ways in which plasticity and selection can interact, based on a review of the literature on selection and phenotypic plasticity in the evolution of populations. The link between selection and phenotypic plasticity is analysed at the level of the individual. Plasticity can affect an individual’s response to selection and so may modify the end result of genetic diversity evolution at population level. Genetic diversity increases the ability of populations or communities to adapt to new environmental conditions. Adaptive plasticity increases individual fitness. However this effect must be viewed from the perspective of the costs of plasticity, although these are not easy to estimate. It is becoming necessary to engage in new experimental research to demonstrate the combined effects of selection and plasticity for adaptation and their consequences on the evolution of genetic diversity.
The persistence of a plant population under a specific local climatic regime requires phenotypic adaptation with underlying particular combinations of alleles at adaptive loci. The level of allele ...diversity at adaptive loci within a natural plant population conditions its potential to evolve, notably towards adaptation to a change in climate. Investigating the environmental factors that contribute to the maintenance of adaptive diversity in populations is thus worthwhile. Within-population allele diversity at adaptive loci can be partly driven by the mean climate at the population site but also by its temporal variability.
The effects of climate temporal mean and variability on within-population allele diversity at putatively adaptive quantitative trait loci (QTLs) were evaluated using 385 natural populations of Lolium perenne (perennial ryegrass) collected right across Europe. For seven adaptive traits related to reproductive phenology and vegetative potential growth seasonality, the average within-population allele diversity at major QTLs (HeA) was computed.
Significant relationships were found between HeA of these traits and the temporal mean and variability of the local climate. These relationships were consistent with functional ecology theory.
Results indicated that temporal variability of local climate has likely led to fluctuating directional selection, which has contributed to the maintenance of allele diversity at adaptive loci and thus potential for further adaptation.
Variations in mercury (Hg) isotopic compositions have been scarcely investigated until now in the Almadén mining district (Spain), which is one of the most impacted Hg areas worldwide. In this work, ...we explore and compare Hg isotopic signatures in sediments and lichens from Almadén mining district and its surroundings in order to identify and trace Hg aquatic and atmospheric contamination sources. No statistically significant mass independent fractionation was observed in sediments, while negative Δ201Hg values from −0.12 to −0.21‰ (2SD = 0.06‰) were found in lichens. A large range of δ202Hg values were reported in sediments, from −1.86 ± 0.21‰ in La Serena Reservoir sites far away from the pollution sources to δ202Hg values close to zero in sediments directly influenced by Almadén mining district, whereas lichens presented δ202Hg values from −1.95 to −0.40‰ (2SD = 0.15‰). A dilution or mixing trend in Hg isotope signatures versus the distance to the mine was found in sediments along the Valdeazogues River-La Serena Reservoir system and in lichens. This suggests that Hg isotope fingerprints in these samples are providing a direct assessment of Hg inputs and exposure from the mining district, and potential information on diffuse atmospheric contamination and/or geochemical alteration processes in less contaminated sites over the entire hydrosystem. This study confirms the applicability of Hg isotope signatures in lichens and sediments as an effective and complementary tool for tracing aquatic and atmospheric Hg contamination sources and a better constraint of the spatial and temporal fate of Hg released by recent or ancient mining activities.
•Hg isotope signatures have enabled tracing aquatic and atmospheric Hg sources.•Hg isotope composition and contamination displayed a dilution downstream the mines.•MDF of Hg isotopes allowed to track biogeochemical alterations downstream Hg mines.•Sediments and lichens can act as complementary Hg reservoirs as revealed by MIF signatures.•Isotopic data from this emblematic mining district can be used as an isotopic reference.
Geographically based investigations into atmospheric bio-monitoring usually provide information on concentration or occurrence data and spatial trends of specific contaminants over a specified study ...area. In this work, an original approach based on geographic information system (GIS) was used to establish metal contents (Hg, Cu, Pb, and Cd) in epiphytic lichens from 90 locations as atmospheric bio-monitors over a meso-scale area (Pyrénées-Atlantiques, southwestern France). This approach allows the integration of the heterogeneity of the territory and optimization of the sampling sites based on both socioeconomical and geophysical parameters (hereafter defined as urban, industrial, agricultural, and forested areas). The sampling strategy was first evaluated in several sites (n = 15) over different seasons and years in order to follow the temporal variability of the atmospheric metal input in lichens. The results demonstrate that concentration ranges remain constant over different sampling periods in “rural” areas (agricultural and forested). Higher variability is observed in the “anthropized” urban and industrial areas in relation to local atmospheric inputs. In this context, metal concentrations in lichens over the whole study show that (1) Hg and Cd are homogeneous over the whole territory (0.14 ± 0.04 and 0.38 ± 0.26 mg/kg, respectively), whereas (2) Cu and Pb are more concentrated in “anthropized” areas (9.3 and 11.9 mg/kg, respectively) than in “rural” ones (6.8 and 6.0 mg/kg, respectively) (Kruskall-Wallis, K(Cu) = 13.7 and K(Pb) = 9.7, p < 0.00001). They also showed a significant local enrichment for all metals in many locations in the Pays Basque (West) mainly due to metal and steel industrial activities. This confirms the local contribution of this contamination source over a wider geographic scale. A multiple linear regression model was applied to give an integrated spatialization of the data. This showed significant relationships for Pb and Cu (adjusted r²of 0.39 and 0.45, respectively), especially with regards to variables such as industry and road densities (source factors) and elevation or water balance (remote factors). These results show that an integrated GIS-based sampling strategy can improve biomonitoring data distribution and allows better differentiation of local and long-range contamination.
Osteoarthritis (OA), characterized by degeneration of the cartilaginous tissue in articular joints, severely impairs mobility in many people worldwide. The degeneration is thought to be mediated by ...inflammatory processes occurring in the tissue of the joint, including the cartilage. Intra-articular administered triamcinolone acetonide (TAA) is one of the drug treatments employed to ameliorate the inflammation and pain that characterizes OA. However, the penetration and distribution of TAA into the avascular cartilage is not well understood. We employed matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI), which has been previously used to directly monitor the distribution of drugs in biological tissues, to evaluate the distribution of TAA in human cartilage after in vitro incubation. Unfortunately, TAA is not easily ionized by regular electrospray ionization (ESI) or MALDI. To overcome this problem, we developed an on-tissue derivatization method with Girard’s reagent T (GirT) in human incubated cartilage being able to study its distribution and quantify the drug abundance (up to 3.3 ng/μL). Our results demonstrate the depth of penetration of a corticosteroid drug in human OA cartilage using MALDI-MSI.
In this paper, we attempt to analyse the respective influences of land-use and climate changes on the global and regional balances of soil organic carbon (SOC) stocks. Two time periods are analysed: ...the historical period 1901-2000 and the period 2000-2100. The historical period is analysed using a synthesis of published data as well as new global and regional model simulations, and the future is analysed using models only. Historical land cover changes have resulted globally in SOC release into the atmosphere. This human induced SOC decrease was nearly balanced by the net SOC increase due to higher CO
2
and rainfall. Mechanization of agriculture after the 1950s has accelerated SOC losses in croplands, whereas development of carbon-sequestering practices over the past decades may have limited SOC loss from arable soils. In some regions (Europe, China and USA), croplands are currently estimated to be either a small C sink or a small source, but not a large source of CO
2
to the atmosphere.
In the future, according to terrestrial biosphere and climate models projections, both climate and land cover changes might cause a net SOC loss, particularly in tropical regions. The timing, magnitude, and regional distribution of future SOC changes are all highly uncertain. Reducing this uncertainty requires improving future anthropogenic CO
2
emissions and land-use scenarios and better understanding of biogeochemical processes that control SOC turnover, for both managed and un-managed ecosystems.
Left ventricular disease occurs frequently in dialysis patients. It may be manifest as concentric LV hypertrophy, LV dilatation with or without LV hypertrophy, or systolic dysfunction. Little is ...known concerning the clinical outcome and risk factors for these disorders.
A cohort of 432 end-stage renal disease patients who survived at least 6 months had an echocardiogram on initiation of dialysis therapy. Clinical, laboratory and echocardiographic data was obtained annually during follow-up.
On initiation of ESRD therapy 16% of patients had systolic dysfunction, 41% concentric LV hypertrophy, 28% LV dilatation, and only 16% had normal echocardiograms. Median time to development of heart failure was 19 months in patients with systolic dysfunction, 38 months in concentric LV hypertrophy and 38 months in LV dilatation. The relative risks of heart failure in the three groups were significantly worse than in the normal group, after adjusting for age, diabetes and ischaemic heart disease. Median survival was 38 months in systolic dysfunction, 48 months in concentric hypertrophy, 56 months in LV dilatation, and >66 months in the normal group. Two hundred and seventy-five patients had a follow-up echocardiogram 17 months after starting dialysis therapy together with serial measurement of potential risk factors prior to the echocardiogram. On follow-up echocardiogram the degree of concentric LV hypertrophy was independently related to hypertension while on dialysis, older age, and anaemia while on dialysis; the degree of LV dilatation was related to ischaemic heart disease, anaemia, hypertension and hypoalbuminemia while on dialysis; the degree of systolic dysfunction was associated with ischaemic heart disease and anaemia during follow-up.
Manifestations of left ventricular disease are frequent and persistent in chronic uraemia, and are associated with high risks of heart failure and death. Potentially reversible risk factors include anaemia, hypertension, hypoalbuminaemia and ischaemic heart disease.
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