104 research outputs found
Green Plants in the Red: A Baseline Global Assessment for the IUCN Sampled Red List Index for Plants
Plants provide fundamental support systems for life on Earth and are the basis for all terrestrial ecosystems; a decline in plant diversity will be detrimental to all other groups of organisms including humans. Decline in plant diversity has been hard to quantify, due to the huge numbers of known and yet to be discovered species and the lack of an adequate baseline assessment of extinction risk against which to track changes. The biodiversity of many remote parts of the world remains poorly known, and the rate of new assessments of extinction risk for individual plant species approximates the rate at which new plant species are described. Thus the question ‘How threatened are plants?’ is still very difficult to answer accurately. While completing assessments for each species of plant remains a distant prospect, by assessing a randomly selected sample of species the Sampled Red List Index for Plants gives, for the first time, an accurate view of how threatened plants are across the world. It represents the first key phase of ongoing efforts to monitor the status of the world’s plants. More than 20% of plant species assessed are threatened with extinction, and the habitat with the most threatened species is overwhelmingly tropical rain forest, where the greatest threat to plants is anthropogenic habitat conversion, for arable and livestock agriculture, and harvesting of natural resources. Gymnosperms (e.g. conifers and cycads) are the most threatened group, while a third of plant species included in this study have yet to receive an assessment or are so poorly known that we cannot yet ascertain whether they are threatened or not. This study provides a baseline assessment from which trends in the status of plant biodiversity can be measured and periodically reassessed
A Chemical Reactor Network methodology for estimating NOx emissions under non-premixed lean hydrogen combustion with water injection
This study investigates the ability of Chemical Reactor Network (CRN) methodologies in predicting NOx reduction through water injection in a lean non-premixed hydrogen combustor for a given outlet flame temperature. A new methodology for creating a chemical reactor network to analyze emissions is proposed and validated. The novelty lies in the definition of the connections between the different reactors composing the network using an optimization algorithm. This approach allows the prediction of emissions without the need for complete knowledge of the flow field of the combustor through PIV or high-fidelity CFD simulations. The proposed method proves to be a reliable and computationally efficient framework for predicting hydrogen combustion emissions, achieving thousand-fold computational savings over CFD while maintaining prediction accuracy on the NOx emissions within experimental uncertainty. The results are validated through comparisons with CFD simulations, which are first assessed against experimental data without water injection, demonstrating CFD’s effectiveness in this scenario. The CRN, trained without water injection, successfully applies to the water injection cases, demonstrating its predictive capability beyond the training conditions
Isolation and characterisation of a human anti-idiotypic scFv used as a surrogate tumour antigen to elicit an anti-HER-2/neu humoral response in mice
Nuovo approccio all’impiego del mezzo di contrasto organo-iodato: storia di un percorso di implementazione
NFKB1 and Cancer: Friend or Foe?
Current evidence strongly suggests that aberrant activation of the NF-κB signalling pathway is associated with carcinogenesis. A number of key cellular processes are governed by the effectors of this pathway, including immune responses and apoptosis, both crucial in the development of cancer. Therefore, it is not surprising that dysregulated and chronic NF-κB signalling can have a profound impact on cellular homeostasis. Here we discuss NFKB1 (p105/p50), one of the five subunits of NF-κB, widely implicated in carcinogenesis, in some cases driving cancer progression and in others acting as a tumour-suppressor. The complexity of the role of this subunit lies in the multiple dimeric combination possibilities as well as the different interacting co-factors, which dictate whether gene transcription is activated or repressed, in a cell and organ-specific manner. This review highlights the multiple roles of NFKB1 in the development and progression of different cancers, and the considerations to make when attempting to manipulate NF-κB as a potential cancer therapy
Two-dimensional recursive filtering algorithm with edge-preserving properties and reduced numerical complexity
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