309 research outputs found
Heavy metals distribution in mangrove sediments along the mobile coastline of French Guiana.
The accumulation of nine heavy metals in fine-grained sediments from the mangrove fringed coast of French Guiana is evaluated. The dynamic features of the South American tropical coastline, from the Amazon to the Orinoco Rivers, result in mangrove sediments being alternately submitted to phases of erosion and net sedimentation a few tens of years long. This process influences the distribution of the heavy metals associated with these frequently re-mobilized deposits. Sedimentary cores and mangrove plant samples were collected, at different seasons, in various swamps characterized by different properties (content of sedimentary organic matter, distance from sea water and fresh water). The ranges of measured concentrations expressed in mu mol g(-1) were the following: Cu (0.06 to 0.61), Co (0.12 to 0.68), Pb (0.08 to 0.18), Ni (0.32 to 0.76), Cr (0.61 to 1.40), Zn (1.25 to 5.94), Mn (4.36 to 45.4) and Fe (441 to 1128). No differences were found between sediments from mangroves developing upstream and downstream of urban areas, i.e. Cayenne and Kourou. This suggests that the content of mangrove sediments in heavy metals along the coastline of French Guiana is essentially the result of the continuous alternation of accumulation and transport phases occurring upstream after departing from the Amazon watershed. The sources of this heavy metals content are thus difficult to identify. However it is well known that the alluvium produced by the natural erosion of the Amazonian soils is naturally enriched in mercury. Also, the run-off from gold mining activities is known to contribute to mercury pollution. Ranges in total Hg were between 0.15 and 2.57 nmol g(-1), with mean values close to 0.41 nmol g(-1), and were clearly correlated with total organic carbon except for some outstanding high values, which may be a result of rapid geochemical changes. Heavy metal concentrations showed variations with depth. The redox conditions and the decay processes affecting the organic matter control the cycling of iron and manganese, which in turn control the concentrations and associations of heavy metals. These preliminary results suggest that the variations in heavy metal content with depth or between mangrove areas result largely from diagenetic processes rather than changes in metal input resulting from local human activities
Localized inhibition of protein phosphatase 1 by NUAK1 promotes spliceosome activity and reveals a MYC-sensitive feedback control of transcription.
Deregulated expression of MYC induces a dependence on the NUAK1 kinase, but the molecular mechanisms underlying this dependence have not been fully clarified. Here, we show that NUAK1 is a predominantly nuclear protein that associates with a network of nuclear protein phosphatase 1 (PP1) interactors and that PNUTS, a nuclear regulatory subunit of PP1, is phosphorylated by NUAK1. Both NUAK1 and PNUTS associate with the splicing machinery. Inhibition of NUAK1 abolishes chromatin association of PNUTS, reduces spliceosome activity, and suppresses nascent RNA synthesis. Activation of MYC does not bypass the requirement for NUAK1 for spliceosome activity but significantly attenuates transcription inhibition. Consequently, NUAK1 inhibition in MYC-transformed cells induces global accumulation of RNAPII both at the pause site and at the first exon-intron boundary but does not increase mRNA synthesis. We suggest that NUAK1 inhibition in the presence of deregulated MYC traps non-productive RNAPII because of the absence of correctly assembled spliceosomes
Health impacts of industrial mining on surrounding communities: local perspectives from three sub-Saharan African countries
Industrial mining projects can play an important role in global sustainable development if associated health risks are minimised and opportunities maximised. While a broad body of evidence from quantitative studies exists that establishes the interlinkages between mining operations and effects on public health, little research has been conducted investigating health impacts from the perspective of affected communities. This is particularly true in sub-Saharan Africa, where about a third of the remaining global mineral resources are endowed and health-related indicators for sustainable development are lagging behind. In this multi-country qualitative study, we explore community perceptions regarding impacts of industrial mining on their health and well-being. In nine study sites in Burkina Faso, Mozambique and Tanzania, we conducted 83 participatory focus group discussions with a total of 791 participants (385 men, 406 women). Our findings reveal a broad range of perceived impacts on environmental, economic and social determinants of health, with secondary health implications related to morbidity, mortality and well-being. Overall, perceived negative impacts prevailed, mainly related to environmental pollution, change in livelihoods or social disruption. Perceived positive impacts on health and well-being were related to interventions implemented by the mines such as new or improved water sources, health care facilities, roads and schools. The consistency of these findings across countries and study sites suggests a structural problem and indicates a pressing need to address health by acting on the wider determinants of health in mining regions. Participatory health impact assessment should be strengthened in host countries to foster strategic interventions, include marginalised population groups, and protect and promote the health of local communities. By including community perspectives on health before and during project implementation, policymakers can take advantage of economic opportunities while avoiding the pitfalls, bringing their communities closer to achieving good health and well-being goals by 2030 and beyond
Unusual skin toxicity associated with sustained disease response induced by nivolumab in a patient with non-small cell lung cancer
Introduction: Immunotherapy has shown efficacy in the treatment of different malignancies. Nivolumab, an immune checkpoint inhibitor directed against programmed death-1, has been approved for non-small cell lung cancer (NSCLC) in pretreated patients. Although it is generally well-tolerated, immunotherapy may be complicated by a wide range of immune-mediated adverse events. We describe the case of an uncommon skin toxicity arising as alopecia universalis induced by nivolumab in a patient with NSCLC. Case description: A 58-year-old man received nivolumab for metastatic NSCLC after progression to 3 lines of chemotherapy. The treatment was prescribed in June 2016, and induced a rapid and significant disease response. Nivolumab was well-tolerated until May 2017, when partial alopecia at hair and eyelashes appeared. In the next months, alopecia became complete and extended to the whole body surface. The dermatologic picture was compatible with alopecia areata. A topical steroid therapy was attempted, without benefit. The patient refused systemic treatments and is still undergoing nivolumab without new toxicities and with persistent disease response. Conclusions: This case suggests that alopecia areata may be a rare immune-related adverse event of immune checkpoint agents. Its late onset in our patient is uncommon and unexpected, underlining that the risk of nivolumab-induced toxicity is not limited to the beginning of treatment. Despite its rarity, alopecia areata should be considered in the range of adverse events potentially induced by immune checkpoint inhibitors even in the long term. Potential association between toxicity and efficacy of immunotherapy in NSCLC warrants further investigation
Interfacing Sca-1pos Mesenchymal Stem Cells with Biocompatible Scaffolds with Different Chemical Composition and Geometry
An immortalized murine mesenchymal stem cell line (mTERT-MSC) enriched for Linneg/Sca-1pos fraction has been obtained through the transfection of MSC with murine TERT and single-cell isolation. Such cell line maintained the typical MSC self-renewal capacity and continuously expressed MSC phenotype. Moreover, mTERT-MSC retained the functional features of freshly isolated MSC in culture without evidence of senescence or spontaneous differentiation events. Thus, mTERT-MSC have been cultured onto PLA films, 30 and 100 μm PLA microbeads, and onto unpressed and pressed HYAFF-11 scaffolds. While the cells adhered preserving their morphology on PLA films, clusters of mTERT-MSC were detected on PLA beads and unpressed fibrous scaffolds. Finally, mTERT-MSC were not able to colonize the inner layers of pressed HYAFF-11. Nevertheless, such cell line displayed the ability to preserve Sca-1 expression and to retain multilineage potential when appropriately stimulated on all the scaffolds tested
Abilità linguistiche, extralinguistiche e paralinguistiche in pazienti con lesioni focali all’emisfero destro
ESTIMATION OF GENOTYPIC GAIN THROUGH SELECTION IN SEGREGATING GENERATIONS OF OAT
In the selection of superior genotypes, it searches to develop the maximum genetic profit and this to attribute the evaluated traits, in the next cycle of selection, a bigger potential. For thus, it is interesting that the breeder by the genetic improvement knows the efficiency that can be reached when any method of selection in segregating populations is used. Thus, the present work was proposed with the objective of determining the genetic profit considering the differential of estimated selection and the heritability in agronomics traits and quality of grain through selection carried out in segregating generations. The experiment was held in Pato Branco, Brazil, in the southwest region of Paraná State, during the year of 2001. The performed studies have involved the traits vegetative cycle, stature of plant, weight of panicle, number of grains/panicle, average weight of grains and percentage of caryopses in four white oats crossing, UPF 7 X OR 2, UPF 7 X CTC 5, OR 2 X CTC 5 e OR 2 X UPF 18. The heritability coefficients have presented bigger values for the traits vegetative cycle (0,60), average weight of grains (0,68) and percentage of caryopses (0,40). The differential selection was more expressive for the traits directly to the production of grains and, together with the values of heritability, have resulted in high genetic profit considering that the same ones represent a single cycle of selection.A seleção de genótipos superiores busca explorar ao máximo a variância genética aditiva e, com isso, atribuir aos caracteres selecionados, no próximo ciclo de seleção, um maior potencial. Para isso, é interessante que o melhorista conheça a eficiência que pode ser alcançada quando da utilização de um método de seleção em populações segregantes. Assim, o presente trabalho foi proposto com o objetivo de determinar o ganho genotípico, considerando o diferencial de seleção e a herdabilidade no sentido amplo, estimado em caracteres agronômicos e de qualidade do grão da aveia por meio da seleção realizada na geração F3. O experimento foi conduzido no município de Pato Branco, Região Sudoeste do Estado do Paraná, durante o ano de 2001. Os estudos realizados envolveram os caracteres ciclo vegetativo, estatura de planta, peso de panícula, número de grãos/panícola, peso médio de grãos e percentual de cariopse em quatro cruzamentos de aveia branca, UPF 7 X OR 2, UPF 7 X CTC 5, OR 2 X CTC 5 e OR 2 X UPF 18. Os coeficientes de herdabilidade no sentido amplo apresentaram maiores valores para os caracteres ciclo vegetativo (0,60), peso médio de grãos (0,68) e percentual de cariopse (0,40). O diferencial de seleção foi mais expressivo para os caracteres diretamente relacionados a produção de grãos e, juntamente com os valores de herdabilidade no sentido amplo, resultaram em elevado ganho genotípico considerando que os mesmos representaram um único ciclo de seleção
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