Upgrading biogas with novel composite carbon molecular sieve (CCMS) membranes: Experimental and techno-economic assessment

The use of biogas as feedstock for hydrogen production was widely proposed in the literature in the last years as a strategy to reduce anthropogenic carbon emissions. However, its lower heating value compared to natural gas hampers the revamping of existing reforming plants. The use of composite carbon molecular sieve membranes for biogas upgrading (CO2 removal from biogas) was investigated experimentally in this work. In particular, ideal perm-selectivities and permeabilities above the Robeson plot for CO2/CH4 mixtures have been obtained. These membranes show better performances compared to polymeric membranes, which are nowadays commercialized for CO2 separation in natural gas streams. Compared to polymeric membranes, carbon membranes do not show deactivation by plasticization when exposed to CO2, and thus can find industrial application. This work was extended with a techno-economic analysis where carbon membranes are installed in a steam methane reforming plant. Results have been first validated with data from literature and show that the use of biogas increases the costs of hydrogen production to a value of 0.25 €/Nm3 compared to the benchmark technology (0.21 €/Nm3). On the other hand, the use of biogas leads to a decrease in carbon emissions up to 95%, thus the use of biogas for hydrogen production is foreseen as a very interesting alternative to conventional technologies in view of the reduction in the carbon footprint in the novel technologies that are to be installed in the near future

Spontaneous Embedding of DNA Mismatches Within the RNA:DNA Hybrid of CRISPR-Cas9.

CRISPR-Cas9 is the forefront technology for editing the genome. In this system, the Cas9 protein is programmed with guide RNAs to process DNA sequences that match the guide RNA forming an RNA:DNA hybrid structure. However, the binding of DNA sequences that do not fully match the guide RNA can limit the applicability of CRISPR-Cas9 for genome editing, resulting in the so-called off-target effects. Here, molecular dynamics is used to probe the effect of DNA base pair mismatches within the RNA:DNA hybrid in CRISPR-Cas9. Molecular simulations revealed that the presence of mismatched pairs in the DNA at distal sites with respect to the Protospacer Adjacent Motif (PAM) recognition sequence induces an extended opening of the RNA:DNA hybrid, leading to novel interactions established by the unwound nucleic acids and the protein counterpart. On the contrary, mismatched pairs upstream of the RNA:DNA hybrid are rapidly incorporated within the heteroduplex, with minor effect on the protein-nucleic acid interactions. As a result, mismatched pairs at PAM distal ends interfere with the activation of the catalytic HNH domain, while mismatches fully embedded in the RNA:DNA do not affect the HNH dynamics and enable its activation to cleave the DNA. These findings provide a mechanistic understanding to the intriguing experimental evidence that PAM distal mismatches hamper a proper function of HNH, explaining also why mismatches within the heteroduplex are much more tolerated. This constitutes a step forward in understanding off-target effects in CRISPR-Cas9, which encourages novel structure-based engineering efforts aimed at preventing the onset of off-target effects

Equatorial ozone characteristics as measured at Natal (5.9 deg S, 35.2 deg W)

Ozone density profiles obtained through electrochemical concentration cell (ECC) sonde measurements at Natal were analyzed. Time variations, as expected, are small. Outstanding features of the data are tropospheric densities substantially higher than those measured at other stations, and also a total ozone content that is higher than the averages given by satellite measurements

Organization of production and the distribution of labor income in Spain

This paper examines evidences of market labor income inequality in Spain, as if they were the outcome of the market equilibrium from occupational choices of individuals with different general skills. We find that the parameters of the distribution of skills, production technology, and internal organization of firms that match the observed organization of production (number of persons occupied as employees, entrepreneurs-managers and solo self-employed, distribution of firm sizes) in Spain, also explain reasonably well the distribution of market labor income, within groups and for all occupied individuals together. The proposed model can be of use in evaluating the potential consequences for labor income inequality of changes in the organization of production

Firm size and productivity from occupational choices

We model the distributions of firm sizes and of firms’ total factor productivity (TFP) as outcomes of a market equilibrium from the occupational decisions of individuals with different entrepreneurial skills, of working as employees, employers, or solo entrepreneurs. The model explains empirical regularities such as (i) the positive cross-section correlation between average size of firms and average labor productivity of countries, (ii) the positive association between size and TFP of firms in an economy, and (iii) the power law distribution of firm sizes. Two parameters of the model, one that measures the organizational size diseconomies and other related to the dispersion of the distribution of entrepreneurial skills in the population, appear as main determinants of the differences in firm sizes and in productivity, across economies and among firms within an economy. The results of the paper should be of interest for the design and evaluation of firm-size-dependent policies

Estandarización desarrollo y gestión del conocimiento por medio de una capacitación para un en equipo enfocado en el servicio al cliente con vendedores en empresa de tecnología

En un entorno altamente dinámico y competitivo, las empresas necesitan crear ventajas competitivas para seguir en el mercado. La metodología utilizada abarca la mejora de la calidad mediante el uso de herramientas como el diagrama de Ishikawa y el ciclo de Deming consigue implementar de forma sistémica la identificación del problema y las acciones para solucionarlo. Así, como la gestión de conocimiento, para maximizar el talento humano con el que cuentas las organizaciones, mediante el modelo de Nonaka y Taguchi que tiene como objetivo transformar el conocimiento amplío al explícito a través de las personas que integran la organización mediante la creación, retención, transferencia y utilización del conocimiento adquirido. Con el propósito de contribuir a la mejora de procesos de un equipo de asesores, enfocado a asegurar el pago de ventas realizadas. Este equipo cuenta con una oportunidad de mejora en la capacitación e integración de los nuevos miembros que con frecuencia no se les proporciona la información ni formación necesaria para desempeñar sus actividades. Para contrarrestar este problema se ha decidido hacer uso de la gestión del conocimiento y las herramientas de la calidad para generar un sistema de aprendizaje que entrelace la teoría, las experiencias compartidas por un grupo más experimentado y las actividades especialmente diseñadas que le ayuden a desarrollar un pensamiento y criterio sistemático para que posteriormente, la persona sea capaz tomar las decisiones acertadas para cumplir con su trabajo, con los requerimientos que se solicitan.ITESO, A. C

Estandarización desarrollo y gestión del conocimiento por medio de una capacitación para un en equipo enfocado en el servicio al cliente con vendedores en empresa de tecnología

En un entorno altamente dinámico y competitivo, las empresas necesitan crear ventajas para seguir en el mercado. La metodología utilizada abarca la mejora de la calidad mediante el uso de herramientas como el diagrama de Ishikawa y el ciclo de Deming que consigue implementar, de forma sistémica, la identificación del problema, las acciones para solucionarlo y la gestión del conocimiento para maximizar el talento humano con el que cuentan las organizaciones. Mediante el modelo de Nonaka y Taguchi, se tiene como objetivo transformar desde el conocimiento amplio al explícito a través de las personas que integran la organización mediante la creación, retención, transferencia y utilización del conocimiento adquirido; con el propósito de contribuir a la mejora de procesos de un equipo de asesores, enfocado a asegurar el pago de ventas realizadas. Este equipo cuenta con una oportunidad de mejora en la capacitación e integración de los nuevos miembros que, con frecuencia, no se les proporciona la información ni formación necesaria para desempeñar sus actividades. Para contrarrestar este problema se decidió hacer uso de la gestión del conocimiento y las herramientas de la calidad, generando así un sistema de aprendizaje que entrelace la teoría, las experiencias compartidas por un grupo más experimentado y las actividades especialmente diseñadas que ayuden a desarrollar un pensamiento y criterio sistemático; de esta forma la persona será capaz tomar las decisiones acertadas para cumplir con su trabajo, con los requerimientos que se solicitan.ITESO, A. C

Protein interaction perturbation profiling at amino-acid resolution

The identification of genomic variants in healthy and diseased individuals continues to rapidly outpace our ability to functionally annotate these variants. Techniques that both systematically assay the functional consequences of nucleotide-resolution variation and can scale to hundreds of genes are urgently required. We designed a sensitive yeast two-hybrid-based 'off switch' for positive selection of interaction-disruptive variants from complex genetic libraries. Combined with massively parallel programmed mutagenesis and a sequencing readout, this method enables systematic profiling of protein-interaction determinants at amino-acid resolution. We defined >1,000 interaction-disrupting amino acid mutations across eight subunits of the BBSome, the major human cilia protein complex associated with the pleiotropic genetic disorder Bardet–Biedl syndrome. These high-resolution interaction-perturbation profiles provide a framework for interpreting patient-derived mutations across the entire protein complex and thus highlight how the impact of disease variation on interactome networks can be systematically assessed

A new role of the Rac-GAP β2-chimaerin in cell adhesion reveals opposite functions in breast cancer initiation and tumor progression

β2-chimaerin is a Rac1-specific negative regulator and a candidate tumor suppressor in breast cancer but its precise function in mammary tumorigenesis in vivo is unknown. Here, we study for the first time the role of β2-chimaerin in breast cancer using a mouse model and describe an unforeseen role for this protein in epithelial cell-cell adhesion. We demonstrate that expression of β2-chimaerin in breast cancer epithelial cells reduces E-cadherin protein levels, thus loosening cell-cell contacts. In vivo, genetic ablation of β2-chimaerin in the MMTV-Neu/ErbB2 mice accelerates tumor onset, but delays tumor progression. Finally, analysis of clinical databases revealed an inverse correlation between β2-chimaerin and E-cadherin gene expressions in Her2+ breast tumors. Furthermore, breast cancer patients with low β2-chimaerin expression have reduced relapse free survival but develop metastasis at similar times. Overall, our data redefine the role of β2-chimaerin as tumor suppressor and provide the first in vivo evidence of a dual function in breast cancer, suppressing tumor initiation but favoring tumor progression