Cloning, expression and characterisation of a new human low Mr phosphotyrosine protein phosphatase originating by alternative splicing

AbstractRT-PCR experiments on RNA from K562 and HepG2 cells and from human placenta led to the isolation of a novel cDNA, a further alternative splicing product of the primary transcript of low Mr phosphotyrosine phosphatase (LMW-PTP), already known to produce isoforms 1 and 2. This new transcript represents 15–20% of the total LMW-PTP mRNA in the cell. This novel cDNA codifies for a protein that we have named SV3 (splicing variant 3): the deduced protein sequence presents the first 49 residues identical to those of isoform 1, followed by 24 unrelated amino acids, due to a frameshift introduced at the novel exon-exon boundary. The SV3 protein, expressed in E. coli is enzymatically inactive, most probably because unfolded, as suggested by far-UV circular dichroism (CD) experiments. SV3 protein appears to possess the characteristics of an unstructured polypeptide chain lacking the packing of side chain residues and the secondary structure level that are typical of globular proteins. This protein could represent an inactive variant of the human LMW-PTP

Optimización de métodos para el estudio del riesgo asociado a la contaminación fecal del agua y alimentos: cuantificación de patógenos y del riesgo de infecciones virales y análisis metagenómico de virus asociados a hepatitis

El agua es esencial para el sostenimiento de la vida en la tierra, por lo tanto, la calidad debe ser controlada para garantizar su uso de forma segura. Los objetivos planteados en esta tesis están orientados a la optimización de métodos para el estudio del riesgo asociado a la contaminación fecal del agua y alimentos. Este trabajo se dividen en tres secciones: La primera parte busca mejorar las herramientas para cuantificar de una manera más precisa los patógenos y el riesgo microbiológico que tiene el consumo de agua contaminada. En la segunda parte se estima el riesgo microbiológico de la utilización de agua regenerada para el riego de vegetales. En la última parte estudiamos pacientes con hepatitis aguda de etiología desconocida para la valoración de virus emergentes o virus nuevos de posible transmisión fecal-oral como posibles causantes de hepatitis. Los objetivos desarrollados en la presente tesis doctoral han dado lugar a una serie de resultados publicados o en proceso de publicación, las principales conclusiones de estos trabajos fueron: (a) El método SMF pudo ser utilizado eficientemente para concentrar simultáneamente los virus, bacterias y protozoos y se desarrolló un método para estimar la concentración real usando la cuantificaciones obtenidas por q(RT)PCR y la predicción de intervalos al 95% mediante “bootstrap” de las recuperaciones; (b) ninguna de los dos planta evaluadas fueron capaces de superar el umbral de <1.00E-6 DALYs pppy considerado como aceptable por la WHO para irrigar vegetales con agua regenerada y (c) la técnica de secuenciación masiva aplicada en esta tesis permitió detectar una gran variedad de secuencias de especies virales en pacientes con hepatitis y las principales familias identificadas fueron Anelloviridae, Caliciviridae y Astroviridae, todas estas relacionadas con transmisión fecal-oral

Hydrogen Bond Dynamics Near A Micellar Surface: Origin of the Universal Slow Relaxation at Complex Aqueous Interfaces

The dynamics of hydrogen bonds among water molecules themselves and with the polar head groups (PHG) at a micellar surface have been investigated by long molecular dynamics simulations. The lifetime of the hydrogen bond between a PHG and a water molecule is found to be much longer than that between any two water molecules, and is likely to be a general feature of hydrophilic surfaces of organized assemblies. Analyses of individual water trajectories suggest that water molecules can remain bound to the micellar surface for more than a hundred picosecond. The activation energy for such a transition from the bound to a free state for the water molecules is estimated to be about 3.5kcal/mole.Comment: 12 pages. Phys. Rev. Lett. (Accepted) (2002

Role of the Subunits Interactions in the Conformational Transitions in Adult Human Hemoglobin: an Explicit Solvent Molecular Dynamics Study

Hemoglobin exhibits allosteric structural changes upon ligand binding due to the dynamic interactions between the ligand binding sites, the amino acids residues and some other solutes present under physiological conditions. In the present study, the dynamical and quaternary structural changes occurring in two unligated (deoxy-) T structures, and two fully ligated (oxy-) R, R2 structures of adult human hemoglobin were investigated with molecular dynamics. It is shown that, in the sub-microsecond time scale, there is no marked difference in the global dynamics of the amino acids residues in both the oxy- and the deoxy- forms of the individual structures. In addition, the R, R2 are relatively stable and do not present quaternary conformational changes within the time scale of our simulations while the T structure is dynamically more flexible and exhibited the T\rightarrow R quaternary conformational transition, which is propagated by the relative rotation of the residues at the {\alpha}1{\beta}2 and {\alpha}2{\beta}1 interface.Comment: Reprinted (adapted) with permission from J. Phys. Chem. B DOI:10.1021/jp3022908. Copyright (2012) American Chemical Societ

Globalization, Financial Depth, and Inequality in Sub-Saharan Africa

ISSN:0948-3349ISSN:1614-750

Enhancing life cycle impact assessment from climate science: Review of recent findings and recommendations for application to LCA

Since the Global Warming Potential (GWP) was first presented in the Intergovernmental Panel on Climate Change (IPCC) First Assessment Report, the metric has been scrutinized and alternative metrics have been suggested. The IPCC Fifth Assessment Report gives a scientific assessment of the main recent findings from climate metrics research and provides the most up-to-date values for a subset of metrics and time horizons. The objectives of this paper are to perform a systematic review of available midpoint metrics (i.e. using an indicator situated in the middle of the cause-effect chain from emissions to climate change) for well-mixed greenhouse gases and near-term climate forcers based on the current literature, to provide recommendations for the development and use of characterization factors for climate change in life cycle assessment (LCA), and to identify research needs. This work is part of the ‘Global Guidance on Environmental Life Cycle Impact Assessment’ project held by the UNEP/SETAC Life Cycle Initiative and is intended to support a consensus finding workshop. In an LCA context, it can make sense to use several complementary metrics that serve different purposes, and from there get an understanding about the robustness of the LCA study to different perspectives and metrics. We propose a step-by-step approach to test the sensitivity of LCA results to different modelling choices and provide recommendations for specific issues such as the consideration of climate-carbon feedbacks and the inclusion of pollutants with cooling effects (negative metric values)

Bridging the gap between impact assessment methods and climate science

Life-cycle assessment and carbon footprint studies are widely used by decision makers to identify climate change mitigation options and priorities at corporate and public levels. These applications, including the vast majority of emission accounting schemes and policy frameworks, traditionally quantify climate impacts of human activities by aggregating greenhouse gas emissions into the so-called CO2-equivalents using the 100-year Global Warming Potential (GWP100) as the default emission metric. The practice was established in the early nineties and has not been coupled with progresses in climate science, other than simply updating numerical values for GWP100. We review the key insights from the literature surrounding climate science that are at odds with existing climate impact methods and we identify possible improvement options. Issues with the existing approach lie in the use of a single metric that cannot represent the climate system complexity for all possible research and policy contexts, and in the default exclusion of near-term climate forcers such as aerosols or ozone precursors and changes in the Earth’s energy balance associated with land cover changes. Failure to acknowledge the complexity of climate change drivers and the spatial and temporal heterogeneities of their climate system responses can lead to the deployment of suboptimal, and potentially even counterproductive, mitigation strategies. We argue for an active consideration of these aspects to bridge the gap between climate impact methods used in environmental impact analysis and climate science