126 research outputs found

    In vivo inhibition of c-MYC in myeloid cells impairs tumor-associated macrophage maturation and pro-tumoral activities

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    Although tumor-associated macrophages (TAMs) are involved in tumor growth and metastasis, the mechanisms controlling their pro-tumoral activities remain largely unknown. The transcription factor c-MYC has been recently shown to regulate in vitro human macrophage polarization and be expressed in macrophages infiltrating human tumors. In this study, we exploited the predominant expression of LysM in myeloid cells to generate c-Myc(fl/fl) LysM(cre/+) mice, which lack c-Myc in macrophages, to investigate the role of macrophage c-MYC expression in cancer. Under steady-state conditions, immune system parameters in c-Myc(fl/fl) LysM(cre/+) mice appeared normal, including the abundance of different subsets of bone marrow hematopoietic stem cells, precursors and circulating cells, macrophage density, and immune organ structure. In a model of melanoma, however, TAMs lacking c-Myc displayed a delay in maturation and showed an attenuation of pro-tumoral functions (e.g., reduced expression of VEGF, MMP9, and HIF1α) that was associated with impaired tissue remodeling and angiogenesis and limited tumor growth in c-Myc(fl/fl) LysM(cre/+) mice. Macrophage c-Myc deletion also diminished fibrosarcoma growth. These data identify c-Myc as a positive regulator of the pro-tumoral program of TAMs and suggest c-Myc inactivation as an attractive target for anti-cancer therapy

    Biocides in paints in urban areas: Modelling an underestimated source of environmental contamination

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    Biocide contamination of receiving waters is generally linked with agriculture. However, recent studies have shown that urban contributions should be also considered. One of the suspected biocide sources in the urban environment is building paint. Biocides like diuron, irgarol, terbutryn, carbendazim, etc., are conventionally used in paint to control fungi, algae, bacteria and other microorganisms that can colonize building façades. The problem of biocides in urban areas is closely linked to meteorological conditions and in particular to rain events. As a consequence, it is important to understand how rainwater collects and transports biocides from façades and how these biocides are transported in sewer systems to receiving waters. In this study, we present a conceptual model describing façade leaching and couple it with a Wind Driven Rain model and a classical hydrological model to compute the contribution of a city to the biocide load from building paint. For the entire city of Lausanne (Switzerland, 200’000 inhabitants), a global production of 2200 kg/year of terbutryn leached by rain was estimated considering local building characteristics and meteorological information. The leaching model fitted well the peak in concentration measured at the bottom of the wall at the initial stage of the rain event. However, concentrations measured in an urban river in the watershed leads to the conclusion that most of this leachate does not reach directly receiving waters, but is infiltrated into soil or reaches the sewers after some delays in drainage pipes. Release of biocides from façade leaching in the environment is systematic during rain event. It is of greater importance to estimate the dynamic of biocides during rain events and to compare these values with dedicated time varying environmental quality criteria

    Stripping #The Dress: the importance of contextual information on inter-individual differences in colour perception.

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    In 2015, a picture of a Dress (henceforth the Dress) triggered popular and scientific interest; some reported seeing the Dress in white and gold (W&G) and others in blue and black (B&B). We aimed to describe the phenomenon and investigate the role of contextualization. Few days after the Dress had appeared on the Internet, we projected it to 240 students on two large screens in the classroom. Participants reported seeing the Dress in B&B (48%), W&G (38%), or blue and brown (B&Br; 7%). Amongst numerous socio-demographic variables, we only observed that W&G viewers were most likely to have always seen the Dress as W&G. In the laboratory, we tested how much contextual information is necessary for the phenomenon to occur. Fifty-seven participants selected colours most precisely matching predominant colours of parts or the full Dress. We presented, in this order, small squares (a), vertical strips (b), and the full Dress (c). We found that (1) B&B, B&Br, and W&G viewers had selected colours differing in lightness and chroma levels for contextualized images only (b, c conditions) and hue for fully contextualized condition only (c) and (2) B&B viewers selected colours most closely matching displayed colours of the Dress. Thus, the Dress phenomenon emerges due to inter-individual differences in subjectively perceived lightness, chroma, and hue, at least when all aspects of the picture need to be integrated. Our results support the previous conclusions that contextual information is key to colour perception; it should be important to understand how this actually happens

    Scientists’ Warning to Humanity: Rapid degradation of the world\u27s large lakes

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    Large lakes of the world are habitats for diverse species, including endemic taxa, and are valuable resources that provide humanity with many ecosystem services. They are also sentinels of global and local change, and recent studies in limnology and paleolimnology have demonstrated disturbing evidence of their collective degradation in terms of depletion of resources (water and food), rapid warming and loss of ice, destruction of habitats and ecosystems, loss of species, and accelerating pollution. Large lakes are particularly exposed to anthropogenic and climatic stressors. The Second Warning to Humanity provides a framework to assess the dangers now threatening the world\u27s large lake ecosystems and to evaluate pathways of sustainable development that are more respectful of their ongoing provision of services. Here we review current and emerging threats to the large lakes of the world, including iconic examples of lake management failures and successes, from which we identify priorities and approaches for future conservation efforts. The review underscores the extent of lake resource degradation, which is a result of cumulative perturbation through time by long-term human impacts combined with other emerging stressors. Decades of degradation of large lakes have resulted in major challenges for restoration and management and a legacy of ecological and economic costs for future generations. Large lakes will require more intense conservation efforts in a warmer, increasingly populated world to achieve sustainable, high-quality waters. This Warning to Humanity is also an opportunity to highlight the value of a long-term lake observatory network to monitor and report on environmental changes in large lake ecosystems

    Optimization of Recombination in Interspecific Hybrids to Introduce New Genetic Diversity into Oilseed Rape (Brassica napus L.)

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    International audienceBrassica napus (oilseed rape, rapeseed, canola) is an agriculturally important allotetraploid (2n = AACC) species in the Brassica genus. However, due to its recent origin from only a few hybridization events between progenitor diploid species B. rapa (2n = AA) and B. oleracea (2n = CC), and due to stringent breeding selection pressure for oil-quality traits, B. napus has very narrow genetic diversity. This creates a problem for breeders, who need genetic diversity for continual improvement of agronomic traits. Innovative strategies can be proposed using homologous recombination to generate more stable material from crosses with progenitor species B. rapa and B. oleracea as well as related allopolyploids B. juncea (2n = AABB) and B. carinata (2n = BBCC), as all share a genome or subgenome (set of chromosomes) in common with B. napus. These methods are useful for trait introgression into B. napus, whatever their genetic control, as higher recombination frequencies allow a smaller genomic region to be introgressed with less chance of linkage drag. However, useful traits can be also transferred via homeologous pairing (between chromosomes from different genomes) in interspecific hybrids between B. napus and close relatives. This method is difficult and generally results in large genomic introgression regions, with an increased chance of linkage drag (co-introgression of genes with a negative effect on yield traits), but is relevant for traits under monogenic control. The advantages and limitations of each strategy according to the ploidy level of the hybrids are presented
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