Molecular dissection of the nuclear pore complex in relation to nuclear export pathways

The nuclear pore complex (NPC) is the gateway to and from the genome. The work presented in this thesis is the result of the investigations towards understanding some of the key questions affecting NPC biology: How is the NPC built up? Can we dissect different modes of transport at the level of the NPC? Does the NPC play a role in the development of cancer? Several findings presented in this thesis have contributed to the current knowledge of the biology of the Nuclear Pore Complex. Structurally, the hierarchy towards incorporation to the NPC of the cytoplasmic components Nup88, Nup214 and Nup 358 and their relevance to nuclear transport has been established. Concerning nuclear transport itself, a supporting role in CRM1-mediated export has been assigned to Nup358 and an explanation to the weak nature of the interaction of CRM1 and its NES-containing cargoes been elucidated. This work has amplified as well the concept of nuclear translocation by creating a distinction in transport pathways that, instead of been exclusively dependent on the receptor-NPC and the receptor-cargo interactions, consider the characteristics of the cargo itself. In fact , while showing cargos that can be exported by CRM1 independently of Nup214, we present first in vivo evidence of the implication of Nup214 in a NPC gating mechanism for the CRM1-dependent export of preribosomes Furthermore, this result excludes any implication of the strong CRM1 binding Nup214 FG-domain in this mechanism and in other suggested models of CRM1 export. Finally, this thesis has provided information concerning the localization and stability of the aberrant product Nup214-ABL that may be of great value for the development of alternative therapies of leukemic diseasesUBL - phd migration 201

Identification of Hypoxia-Regulated Proteins Using MALDI-Mass Spectrometry Imaging Combined with Quantitative Proteomics

Hypoxia is present in most solid tumors and is clinically correlated with increased metastasis and poor patient survival. While studies have demonstrated the role of hypoxia and hypoxia-regulated proteins in cancer progression, no attempts have been made to identify hypoxia-regulated proteins using quantitative proteomics combined with MALDI-mass spectrometry imaging (MALDI-MSI). Here we present a comprehensive hypoxic proteome study and are the first to investigate changes in situ using tumor samples. In vitro quantitative mass spectrometry analysis of the hypoxic proteome was performed on breast cancer cells using stable isotope labeling with amino acids in cell culture (SILAC). MS analyses were performed on laser-capture microdissected samples isolated from normoxic and hypoxic regions from tumors derived from the same cells used in vitro. MALDI-MSI was used in combination to investigate hypoxia-regulated protein localization within tumor sections. Here we identified more than 100 proteins, both novel and previously reported, that were associated with hypoxia. Several proteins were localized in hypoxic regions, as identified by MALDI-MSI. Visualization and data extrapolation methods for the in vitro SILAC data were also developed, and computational mapping of MALDI-MSI data to IHC results was applied for data validation. The results and limitations of the methodologies described are discussed. 2014 American Chemical Societ

Salmonella Shedding in Slaughter Pigs and the Use of Esterified Formic Acid in the Drinking Water as a Potential Abattoir-Based Mitigation Measure

Pigs shedding Salmonella at slaughter are considered a source of carcass contamination and human infection. To assess this potential risk, the proportion of Salmonella shedders that arrive for slaughter was evaluated in a population of 1068 pigs from 24 farms. Shedding was present in 27.3% of the pigs, and the monophasic variant of Salmonella Typhimurium, an emerging zoonotic serotype, was the most prevalent (46.9%). Antimicrobial resistance (AMR) in Salmonella isolates was common, but few isolates showed AMR to antimicrobials of critical importance for humans such as third-generation cephalosporins (5%), colistin (0%), or carbapenems (0%). However, AMR to tigecycline was moderately high (15%). The efficacy of an esterified formic acid in the lairage drinking water (3 kg formic acid/1000 L) was also assessed as a potential abattoir-based strategy to reduce Salmonella shedding. It was able to reduce the proportion of shedders (60.7% in the control group (CG) vs. 44.3% in the treatment group (TG); p < 0.01). After considering clustering and confounding factors, the odds of shedding Salmonella in the CG were 2.75 (95% CI = 1.80–4.21) times higher than those of the TG, suggesting a potential efficacy of reduction in shedding as high as 63.6%. This strategy may contribute to mitigating the burden of abattoir environmental contamination

Reflections on the future business model of European banks and the supervisory approach

Relevant forces are reshaping the banking sector and redefining banks’ business models. On the one hand, banks have been facing structural difficulties, such as a prolonged low interest rate environment and the costs of excess capacity. In addition, banks need to deal with more recently developing challenges, like the digital transformation, the entrance of new competitors in the banking sector and the climate change. A demanding regulatory environment and the impact of the COVID-19 pandemic further aggravate the situation. As a result, European banks are not being able to produce enough returns to cover their cost of capital, making it necessary to urgently face these challenges. To that purpose, banks may adopt different strategies, some of them complementary, among which the following can be highlighted: the reduction of overcapacity, consolidation, diversification or specialisation and the exploitation of the value of long-term relations with clients, as well as taking advantage of the opportunities stemming from digitalization and sustainable finance. Supervisors will need to stay abreast of the changes in the banking environment and closely monitor the adaptation processes. This article is intended to serve as a basis for discussion, given that several of the issues raised are controversial and uncertain under the current fast changing environment

Reflections on the future business model of European banks and the supervisory approach

Importantes factores están reconfigurando el sector bancario y redefiniendo los modelos de negocio de las entidades. Las entidades han venido afrontando dificultades estructurales, como un entorno de bajos tipos de interés prolongado o el exceso de capacidad instalada. A esto se añaden otros retos más recientes, como la transformación digital, los nuevos competidores en el mercado bancario y el cambio climático. Adicionalmente, un entorno regulatorio exigente y el impacto del COVID-19 suponen una presión añadida. Como resultado, los bancos europeos no están siendo capaces de producir resultados que cubran el coste del capital, lo que hace necesario afrontar con urgencia estos retos. Para ello, existen distintas estrategias posibles, algunas de ellas complementarias, entre las que se pueden destacar: la reducción de la capacidad instalada, la consolidación bancaria, la diversificación o especialización y la explotación del valor de la banca relacional, así como el aprovechamiento de las oportunidades derivadas de la digitalización y las finanzas sostenibles. El supervisor deberá estar al nivel de los cambios que se produzcan en el entorno bancario y seguir de cerca los procesos de adaptación. El propósito de este artículo es servir de base para el debate, dada la controversia existente y la incertidumbre que rodea a algunas de estas cuestiones en un entorno como el actual, que cambia con rapidez

Properties of Graphene: A Theoretical Perspective

In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the physical properties of graphene in an external magnetic field, reflecting the chiral nature of the quasiparticles near the Dirac point with a Landau level at zero energy. We address the unique integer quantum Hall effects, the role of electron correlations, and the recent observation of the fractional quantum Hall effect in the monolayer graphene. The quantum Hall effect in bilayer graphene is fundamentally different from that of a monolayer, reflecting the unique band structure of this system. The theory of transport in the absence of an external magnetic field is discussed in detail, along with the role of disorder studied in various theoretical models. We highlight the differences and similarities between monolayer and bilayer graphene, and focus on thermodynamic properties such as the compressibility, the plasmon spectra, the weak localization correction, quantum Hall effect, and optical properties. Confinement of electrons in graphene is nontrivial due to Klein tunneling. We review various theoretical and experimental studies of quantum confined structures made from graphene. The band structure of graphene nanoribbons and the role of the sublattice symmetry, edge geometry and the size of the nanoribbon on the electronic and magnetic properties are very active areas of research, and a detailed review of these topics is presented. Also, the effects of substrate interactions, adsorbed atoms, lattice defects and doping on the band structure of finite-sized graphene systems are discussed. We also include a brief description of graphane -- gapped material obtained from graphene by attaching hydrogen atoms to each carbon atom in the lattice.Comment: 189 pages. submitted in Advances in Physic

NOX2, p22phox and p47phox are targeted to the nuclear pore complex in ischemic cardiomyocytes colocalizing with local reactive oxygen species.

BACKGROUND: NADPH oxidases play an essential role in reactive oxygen species (ROS)-based signaling in the heart. Previously, we have demonstrated that (peri)nuclear expression of the catalytic NADPH oxidase subunit NOX2 in stressed cardiomyocytes, e.g. under ischemia or high concentrations of homocysteine, is an important step in the induction of apoptosis in these cells. Here this ischemia-induced nuclear targeting and activation of NOX2 was specified in cardiomyocytes. METHODS: The effect of ischemia, mimicked by metabolic inhibition, on nuclear localization of NOX2 and the NADPH oxidase subunits p22(phox) and p47(phox), was analyzed in rat neonatal cardiomyoblasts (H9c2 cells) using Western blot, immuno-electron microscopy and digital-imaging microscopy. RESULTS: NOX2 expression significantly increased in nuclear fractions of ischemic H9c2 cells. In addition, in these cells NOX2 was found to colocalize in the nuclear envelope with nuclear pore complexes, p22(phox), p47(phox) and nitrotyrosine residues, a marker for the generation of ROS. Inhibition of NADPH oxidase activity, with apocynin and DPI, significantly reduced (peri)nuclear expression of nitrotyrosine. CONCLUSION: We for the first time show that NOX2, p22(phox) and p47(phox) are targeted to and produce ROS at the nuclear pore complex in ischemic cardiomyocytes

Modeling of a stand-alone solar photovoltaic water pumping system for irrigation

Solar photovoltaic water pumping systems have been research topics in recent decades. The purpose was to develop much more profitable and efficient systems to meet the needs of pumping water for livestock and irrigation. This paper describes the design of a stand-alone photovoltaic water pumping system. A Boost converter is used to apply the Maximum Power Point Tracking (MPPT) algorithm. Similarly, a three-phase voltage source converter (VSC) is used to supply the asynchronous motor. The installation must provide a continuous water flow during the irrigation interval. It has been verified that in adverse weather conditions (cloud transits or partly cloudy) it is necessary to incorporate a decentralized-hybrid energy storage system (based on batteries or ultracapacitors), or excessively oversize the standalone photovoltaic system, to supply the water pump. The model has been simulated in Matlab-Simulink. In this way, different simulations have been developed to verify the basic characteristics of the proposed system. The results of the simulated model and the conclusions obtained are also presented in this paper