91 research outputs found
RENEB accident simulation exercise
Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event.
Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners.
Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes).
Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested
Novel Loss of Function Variant in BCKDK Causes a Treatable Developmental and Epileptic Encephalopathy.
peer reviewedBranched-chain amino acids (BCAA) are essential amino acids playing crucial roles in protein synthesis and brain neurotransmission. Branched-chain ketoacid dehydrogenase (BCKDH), the flux-generating step of BCAA catabolism, is tightly regulated by reversible phosphorylation of its E1α-subunit. BCKDK is the kinase responsible for the phosphorylation-mediated inactivation of BCKDH. In three siblings with severe developmental delays, microcephaly, autism spectrum disorder and epileptic encephalopathy, we identified a new homozygous in-frame deletion (c.999_1001delCAC; p.Thr334del) of BCKDK. Plasma and cerebrospinal fluid concentrations of BCAA were markedly reduced. Hyperactivity of BCKDH and over-consumption of BCAA were demonstrated by functional tests in cells transfected with the mutant BCKDK. Treatment with pharmacological doses of BCAA allowed the restoring of BCAA concentrations and greatly improved seizure control. Behavioral and developmental skills of the patients improved to a lesser extent. Importantly, a retrospective review of the newborn screening results allowed the identification of a strong decrease in BCAA concentrations on dried blood spots, suggesting that BCKDK is a new treatable metabolic disorder probably amenable to newborn screening programs
Myoferlin targeting triggers mitophagy and primes ferroptosis in pancreatic cancer cells
Myoferlin, an emerging oncoprotein, has been associated with a low survival in several cancer types including pancreas ductal adenocarcinoma where it controls mitochondria structure and respiratory functions. Owing to the high susceptibility of KRAS-mutated cancer cells to iron-dependent cell death, ferroptosis, and to the high iron content in mitochondria, we investigated the relation existing between mitochondrial integrity and iron-dependent cell death. We discovered that myoferlin targeting with WJ460 pharmacological compound triggered mitophagy and ROS accumulation culminating with lipid peroxidation and apoptosis-independent cell death. WJ460 caused a reduction of the abundance of ferroptosis core regulators xc- cystine/glutamate transporter and GPX-4. Mitophagy inhibitor Mdivi1 and iron chelators inhibited the myoferlin-related ROS production and restored cell growth. Additionally, we reported a synergic effect between ferroptosis inducers, erastin and RSL3, and WJ460
Tumor resistance to ferroptosis driven by Stearoyl-CoA Desaturase-1 (SCD1) in cancer cells and Fatty Acid Biding Protein-4 (FABP4) in tumor microenvironment promote tumor recurrence.
PROBLEM: Tumor recurrence is a major clinical issue that represents the principal cause of cancer-related deaths, with few targetable common pathways. Mechanisms by which residual tumors persist and progress under a continuous shift between hypoxia-reoxygenation after neoadjuvent-therapy are unknown. In this study, we investigated the role of lipid metabolism and tumor redox balance in tumor recurrence. METHODS: Lipidomics, proteomics and mass spectrometry imaging approaches where applied to mouse tumor models of recurrence. Genetic and pharmacological inhibitions of lipid mediators in tumors were used in vivo and in functional assays in vitro. RESULTS: We found that stearoyl-CoA desaturase-1 (SCD1) expressed by cancer cells and fatty acid binding protein-4 (FABP4) produced by tumor endothelial cells (TECs) and adipocytes in the tumor microenvironment (TME) are essential for tumor relapse in response to tyrosine kinase inhibitors (TKI) and chemotherapy. SCD1 and FABP4 were also found upregulated in recurrent human breast cancer samples and correlated with worse prognosis of cancer patients with different types of tumors. Mechanistically, SCD1 leads to fatty acid (FA) desaturation and FABP4 derived from TEM enhances lipid droplet (LD) in cancer cells, which cooperatively protect from oxidative stress-induced ferroptosis. We revealed that lipid mobilization and desaturation elicit tumor intrinsic antioxidant and anti-ferroptotic resources for survival and regrowth in a harsh TME. Inhibition of lipid transport from TME by FABP4 inhibitor reduced tumor regrowth and by genetic - or by pharmacological - targeting SCD1 in vivo, tumor regrowth was abolished completely. CONCLUSION: This finding unveils that it is worth taking advantage of tumor lipid addiction, as a tumor vulnerability to design novel treatment strategy to prevent cancer recurrence
When Flexibility Is Stable: Implicit Long-Term Shaping of Olfactory Preferences
Preferences are traditionally assumed to be stable. However, empirical evidence such as preference modulation following choices calls this assumption into question. The evolution of such postchoice preference over long time spans, even when choices have been explicitly forgotten, has so far not been studied. In two experiments, we investigated this question by using a variant of the free choice paradigm: In a first session, participants evaluated the pleasantness of a number of odors. We then formed pairs of similarly rated odors, and asked participants to choose their favorite, for each pair. Participants were then presented with all odors again, and asked for another pleasantness rating. In a second session 1 week later, a third pleasantness rating was obtained, and participants were again asked to choose between the same options. Results suggested postchoice preference modulation immediately and 1 week after choice for both chosen and rejected options, even when choices were not explicitly remembered. A third experiment, using another paradigm, confirmed that choice can have a modulatory impact on preferences, and that this modulation can be long-lasting. Taken together, these findings suggest that although preferences appear to be flexible because they are modulated by choices, this modulation also appears to be stable over time and even without explicit recollection of the choice. These results bring a new argument to the idea that postchoice preference modulation could rely on implicit mechanisms, and are consistent with the recent proposal that cognitive dissonance reduction could to some extent be implicit
The Forest Observation System, building a global reference dataset for remote sensing of forest biomass
International audienceForest biomass is an essential indicator for monitoring the Earth's ecosystems and climate. It is a critical input to greenhouse gas accounting, estimation of carbon losses and forest degradation, assessment of renewable energy potential, and for developing climate change mitigation policies such as REDD+, among others. Wall-to-wall mapping of aboveground biomass (aGB) is now possible with satellite remote sensing (RS). However, RS methods require extant, up-to-date, reliable, representative and comparable in situ data for calibration and validation. Here, we present the Forest Observation System (FOS) initiative, an international cooperation to establish and maintain a global in situ forest biomass database. aGB and canopy height estimates with their associated uncertainties are derived at a 0.25 ha scale from field measurements made in permanent research plots across the world's forests. all plot estimates are geolocated and have a size that allows for direct comparison with many RS measurements. The FOS offers the potential to improve the accuracy of RS-based biomass products while developing new synergies between the RS and ground-based ecosystem research communities
The global abundance of tree palms
Aim Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location Tropical and subtropical moist forests. Time period Current. Major taxa studied Palms (Arecaceae). Methods We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., â„10 cm diameter at breast height) abundance relative to coâoccurring nonâpalm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of longâterm climate stability. Lifeâform diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many nonâtree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of aboveâground biomass, but the magnitude and direction of the effect require additional work. Conclusions Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests
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The number of tree species on Earth.
One of the most fundamental questions in ecology is how many species inhabit the Earth. However, due to massive logistical and financial challenges and taxonomic difficulties connected to the species concept definition, the global numbers of species, including those of important and well-studied life forms such as trees, still remain largely unknown. Here, based on global ground-sourced data, we estimate the total tree species richness at global, continental, and biome levels. Our results indicate that there are âŒ73,000 tree species globally, among which âŒ9,000 tree species are yet to be discovered. Roughly 40% of undiscovered tree species are in South America. Moreover, almost one-third of all tree species to be discovered may be rare, with very low populations and limited spatial distribution (likely in remote tropical lowlands and mountains). These findings highlight the vulnerability of global forest biodiversity to anthropogenic changes in land use and climate, which disproportionately threaten rare species and thus, global tree richness
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