University of Lisbon

About: University of Lisbon is a education organization based out in Lisbon, Lisboa, Portugal. It is known for research contribution in the topics: Population & European union. The organization has 19122 authors who have published 48503 publications receiving 1102623 citations. The organization is also known as: Universidade de Lisboa & Lisbon University.

Thermal state of permafrost and active-layer monitoring in the Antarctic: advances during the International Polar Year 2007-2009

Abstract: Results obtained during the International Polar Year (IPY) on the thermal state of permafrost and the active layer in the Antarctic are presented, forming part of ANTPAS (‘Antarctic Permafrost and ...

Current Status and Future Prospects of the SNO+ Experiment

Abstract: SNO+ is a large liquid scintillator-based experiment located 2km underground at SNOLAB, Sudbury, Canada. It reuses the Sudbury Neutrino Observatory detector, consisting of a 12m diameter acrylic vessel which will be filled with about 780 tonnes of ultra-pure liquid scintillator. Designed as a multipurpose neutrino experiment, the primary goal of SNO+ is a search for the neutrinoless double-beta decay (0$ u\beta\beta$) of 130Te. In Phase I, the detector will be loaded with 0.3% natural tellurium, corresponding to nearly 800 kg of 130Te, with an expected effective Majorana neutrino mass sensitivity in the region of 55-133 meV, just above the inverted mass hierarchy. Recently, the possibility of deploying up to ten times more natural tellurium has been investigated, which would enable SNO+ to achieve sensitivity deep into the parameter space for the inverted neutrino mass hierarchy in the future. Additionally, SNO+ aims to measure reactor antineutrino oscillations, low-energy solar neutrinos, and geoneutrinos, to be sensitive to supernova neutrinos, and to search for exotic physics. A first phase with the detector filled with water will begin soon, with the scintillator phase expected to start after a few months of water data taking. The 0$ u\beta\beta$ Phase I is foreseen for 2017.

Responses and impacts of atmospheric rivers to climate change

Abstract: Atmospheric rivers (ARs) are characterized by intense moisture transport, which, on landfall, produce precipitation which can be both beneficial and destructive. ARs in California, for example, are known to have ended drought conditions but also to have caused substantial socio-economic damage from landslides and flooding linked to extreme precipitation. Understanding how AR characteristics will respond to a warming climate is, therefore, vital to the resilience of communities affected by them, such as the western USA, Europe, East Asia and South Africa. In this Review, we use a theoretical framework to synthesize understanding of the dynamic and thermodynamic responses of ARs to anthropogenic warming and connect them to observed and projected changes and impacts revealed by observations and complex models. Evidence suggests that increased atmospheric moisture (governed by Clausius–Clapeyron scaling) will enhance the intensity of AR-related precipitation — and related hydrological extremes — but with changes that are ultimately linked to topographic barriers. However, due to their dependency on both weather and climate-scale processes, which themselves are often poorly constrained, projections are uncertain. To build confidence and improve resilience, future work must focus efforts on characterizing the multiscale development of ARs and in obtaining observations from understudied regions, including the West Pacific, South Pacific and South Atlantic. Due to their intense moisture transport, atmospheric rivers are associated with hydrological hazards such as extreme rainfall and flooding. This Review discusses how atmospheric-river characteristics and impacts may change with warming, synthesizing physical theory, observations and modelling.

The Roles of Peroxiredoxin and Thioredoxin in Hydrogen Peroxide Sensing and in Signal Transduction.

Abstract: A challenge in the redox field is the elucidation of the molecular mechanisms, by which H2O2 mediates signal transduction in cells This is relevant since redox pathways are disturbed in some pathologies The transcription factor OxyR is the H2O2 sensor in bacteria, whereas Cys-based peroxidases are involved in the perception of this oxidant in eukaryotic cells Three possible mechanisms may be involved in H2O2 signaling that are not mutually exclusive In the simplest pathway, H2O2 signals through direct oxidation of the signaling protein, such as a phosphatase or a transcription factor Although signaling proteins are frequently observed in the oxidized state in biological systems, in most cases their direct oxidation by H2O2 is too slow (10(1) M(-1)s(-1) range) to outcompete Cys-based peroxidases and glutathione In some particular cellular compartments (such as vicinity of NADPH oxidases), it is possible that a signaling protein faces extremely high H2O2 concentrations, making the direct oxidation feasible Alternatively, high H2O2 levels can hyperoxidize peroxiredoxins leading to local building up of H2O2 that then could oxidize a signaling protein (floodgate hypothesis) In a second model, H2O2 oxidizes Cys-based peroxidases that then through thiol-disulfide reshuffling would transmit the oxidized equivalents to the signaling protein The third model of signaling is centered on the reducing substrate of Cys-based peroxidases that in most cases is thioredoxin Is this model, peroxiredoxins would signal by modulating the thioredoxin redox status More kinetic data is required to allow the identification of the complex network of thiol switches