Assessment of the neuroprotective potential of poly-arginine peptides in stroke models

Currently, there is no available neuroprotective treatment for reducing acute brain injury following stroke. Recent studies have demonstrated that poly-arginine and arginine-rich peptides (e.g. R18; R = arginine residues) exhibit potent neuroprotective properties in both in vitro and in vivo stroke models, and therefore have the potential to be developed into a neuroprotective treatment for stroke. Consequently, the aim of this thesis was to further assess the neuroprotective efficacy of several poly-arginine and arginine-rich peptides in permanent and transient middle cerebral artery occlusion (MCAO) stroke models in the rat. The poly-arginine peptides R12, R15, R18 and the arginine-rich peptide protamine were assessed in a permanent MCAO model when administered intravenously 30 minutes after stroke onset. Treatment with R12, R18 and protamine significantly reduced infarct volume in this model. In a subsequent dose response study (100, 300,1000nmol/kg) with the lead R18 peptide, when administered intravenously 60 minutes after stroke onset using the permanent MCAO model, infarct volume was reduced by 12 - 24%. Surprisingly, the well characterised neuroprotective peptide TAT-NR2B9c, clinically known as NA-1, which was used as a positive control did not exhibit any significant neuroprotection. When examining R18 efficacy in a milder transient/reperfusion 90-minute MCAO stroke model, the peptide provided significant neuroprotection. R18 decreased infarct volume by 24 and 35% when administered intravenously 60 minutes post-occlusion at the 300 and 1000nmol/kg doses. In comparison, NA-1 decreased infarct volume by 16 and 26% at the same doses. In addition, R18 had a significantly greater beneficial effect in reducing cerebral oedema, when compared to NA-1 treatment. Following the positive results obtained with R18 when administered 60 minutes after stroke onset, its therapeutic window was further investigated. The effectiveness of R18 was examined when administered intravenously 2-hours after the onset of permanent MCAO or transient MCAO of 180-minutes duration, or when administered intra-arterially immediately after reperfusion following a 120-minute duration of MCAO. R18 did not significantly reduced infarct volume in these studies. However, following permanent MCAO R18 significantly reduced cerebral oedema. NA-1 was also ineffective in the transient MCAO studies. The findings presented in this thesis have further confirmed the neuroprotective properties of several poly-arginine and arginine-rich peptides. Although additional studies are still required to evaluate R18 as a neuroprotective agent in stroke, the peptide represents a promising lead agent with the findings of this thesis laying the foundation for future pre-clinical and clinical studies

Characterizing flood impact on Swiss floodplains using inter-annual time series of satellite imagery

Pressure on the biodiversity of ecosystems along many rivers is growing continuously due to the increasing number of hydropower facilities regulating downstream flow and sediment regimes. Despite a thorough understanding of the shortterm processes and interactions at this hydro-biosphere interface, long-term analyses of the impacts on floodplain dynamics are lacking. We used inter-annual Landsat 4, 5, 7 and 8 time series to analyze the effects of hydrological events on floodplain vegetation in four mountainous floodplains in the Swiss Alps. Using a spectral mixture analysis approach, we demonstrate that the floodplain vegetation dynamics of mountainous rivers can be recovered at a spatial resolution of 30 meters. Our results suggest that interactions between floods and floodplain vegetation are complex and not exclusively related to flood magnitude. Of the four reaches analyzed, only data gathered along the submountainous reach with a quasi-natural flow regime show a clear link between remotely sensed vegetation indices and floods. In addition, our 29-year time series shows a continuous upward trend in vegetation indices along the floodplains, strongest in the reaches affected by hydropower facilities. The approach presented in this study can be easily replicated in other mountain ranges by providing available flow data to verify the impact of hydropower on floodplain vegetation dynamics

The cost optimal methodology for evaluating the energy retrofit of an ex-industrial building in Turin.

The recast of the Directive on the Energy Performance of Buildings (EPBD) requires Member States to set minimum energy performance requirements, for buildings, on the cost-optimal level. In Italy, the EPBD recast was transposed in a document (published in GU 2012/C 115) orienting the delegated regulation 244/2012 EU. Following cost-optimal methodology different energy efficiency measures were applied to an abandoned industrial building in Turin, Northern Italy, in order to identify the best retrofit configuration in terms of energy and cost effectiveness

Experimental and Numerical Analysis of a Liquid Aluminium Injector for an Al-H2O based Hydrogen Production System

Abstract This paper investigates pressurized injection system for liquid aluminium for a cogeneration system based on the Al – H2O reaction. The reaction produces hydrogen and heat which is used for super-heating vapour for a steam cycle. The aluminium combustion with water generates also alumina as a byproduct; the aluminium oxide can be recycled and transformed back to aluminium. Thus, aluminium can be exploited as energy carrier in order to transport energy from the alumina recycling plant to the place where the cogeneration system is located. The water is also used in a closed loop; indeed, the amount of water produced employing the hydrogen obtained by the proposed system corresponds to the oxidizing water for the Al/H2O reaction. The development of a specific test rig designed for investigating the liquid aluminium injection is presented in this research study. The injector nozzle is investigated by means of numerical thermal and structural analysis. The calculations are compared and validated against the experimental measurements carried out on ad-hoc developed test rig. A good agreement between the numerical results and the experimental values is found and the new design of the nozzle is devised

A case of a paraduodenal hernia with a concomitant mesosigmoid defect

Abstrac

Análise do evento Cosplay Lavras: reflexões sobre heterotopias

Tomando por base um evento que ocorreu em 2017 na cidade de Lavras, Minas Gerais, foi possí­vel identificar elementos de heterotopias e micro-utopias junto aos participantes. Também foi explicitada a participação e aproximação de elementos artí­sticos e até mesmo cientí­ficos na elaboração de roupas e ferramentas dos chamados cosplays, ou seja, pessoas caracterizadas como determinados personagens de alguma mí­dia ou obra especifica. Tal evento caracteriza uma zona autônoma e temporária de resistência contra determinadas pressões socioculturais, e assim traz elementos diversos para a construção de uma reflexão sobre os espaços fora dos outros lugares. A participação crescente e cada vez mais democrática também serve de termômetro social da necessidade de ambientes livres de imposições e conceitos pré-determinados pela sociedade no qual se busca algo além de auto-afirmação, mas sim um encontro com aquilo e aqueles que compreendem suas percepções de valores e de mundo