The electrochemistry of zinc deposition

PhD ThesisTwo topics have been carried out in the thesis; a development of an on-line computing method for the investigation of electrode reactions and an investigation of the kinetics of zinc deposition from aqueous chloride solutions at pH 3. The first topic was to assess the possibility of analysing a current time response to a small amplitude potential using a Laplace transform and Fourier transform method. The development work was successful, and the system was experimentally tested on the lead ion reduction. This is a stringent test for the method as the reaction is fast compared to diffusion of lead ions in the solution. The method was then applied to the zinc ion reduction on mercury. Further measurements were carried out on the zinc ion reduction on Hg and zinc amalgams by impedance and other electrochemical methods. Finally the reduction of zinc ions on solid zinc was investigated. A mechanism for the zinc ion reduction is proposed

EL SÍNODO AMAZÓNICO, LA AMAZONÍA Y LA IGLESIA

El artículo destaca la particularidad de un Sínodo sobre la Amazonía y sus efectos posibles para la Iglesia Católica, tanto local como globalmente, en la mayor región de bosque tropical del planeta. Posee no sólo una tremenda bio­diversidad sino también una gran diversidad cultural. Esta va desde los pueblos originarios, presentes en la Amazonía miles de años antes de la llegada de los europeos, hasta las complejas formaciones demográficas urbanas y rurales actuales. Describe los procesos preliminares desarrollados en la preparación del Sínodo, plantea algunos de los desafíos contemporáneos para la Amazonía y propone algunas de las características de una iglesia con rostro Amazónico que podrán también influenciar en la iglesia Universal

1D and 2D neutral particle patterning by dielectrophoretic forces on z-cut Fe:LiNbO3 crystals

1D and 2D patterning of uncharged micro- and nanoparticles via dielectrophoretic forces on photovoltaic z-cut Fe:LiNbO3 have been investigated for the first time. The technique has been successfully applied with dielectric micro-particles of CaCO3 (diameter d = 1-3 μm) and metal nanoparticles of Al (d = 70 nm). At difference with previous experiments in x- and y-cut, the obtained patterns locally reproduce the light distribution with high fidelity. A simple model is provided to analyse the trapping process. The results show the remarkably good capabilities of this geometry for high quality 2D light-induced dielectrophoretic patterning overcoming the important limitations presented by previous configurations

Photovoltaic tweezers an emergent tool for applications in nano and bio-technology

An overview of the work recently conducted by our group on the development and applications of photovoltaic tweezers is presented. It includes the analysis of the physical basis of the method and the main achievements in its experimental implementation. Particular attention will be paid to the main potential applications and first demonstrations of its use in nano- and bio-technology. Specifically: i) fabrication of metallic nanoestructures for plasmonic applications, ii) development of diffractive components, iii) manipulation and patterning (1D and 2D) of various types of bio-objects (spores or pollen...) and iv) effects of PV fields of LiNbO3 in tumour cells

Method for incorporating awareness mechanisms in driving simulation environments

The graphical user interface becomes an important element in simulation systems. The problem in this type of systems is that there is plenty of information in the environment that is not provided in the best way to the user. This information can be provided through mechanisms of awareness. However, how to incorporate these mechanisms to the graphical interface of a traffic system is not easy. This paper proposes a method that allows graphical interfaces designers to incorporate awareness mechanisms in driving simulation environments. This method allows engineers to design usable interfaces that simulate reality more adequately

Comparison of available equations to estimate sit-to-stand muscle power and their association with gait speed and frailty in older people: Practical applications for the 5-rep sit-to-stand test

This study aimed i) to compare relative sit-to-stand power (STSrel) values yielded by the different equations reported in the literature; ii) to examine the associations between STSrel, derived from the equations, and age, sex, frailty and habitual gait speed (HGS); and iii) to compare the ability of the different STSrel equations to detect frailty and low HGS in older adults. 1568 participants (>65 years) were included. STSrel was calculated according to four validated equations. Frailty was assessed using the Frailty Trait Scale and HGS as the time to complete 3 m. ANOVA tests, regression analyses and receiver operator characteristic curves were used. There were significant differences among the STSrel values yielded by all the equations, which were higher in men compared to women and negatively associated with age (r = −0.21 to −0.37). STSrel was positively and negative associated to HGS and frailty, respectively, in both men (r = 0.29 to 0.36 and r = −0.18 to −0.45) and women (r = 0.23 to 0.45 and r = −0.09 to −0.57) regardless of the equation used. Area under the curve values varied between 0.68 and 0.80 for Alcazar's, 0.67–0.80 for Ruiz-Cárdenas's, 0.51–0.65 for Smith's, and 0.68–0.80 for Takai's equations. Low STSrel indicated an increased probability of having both low HGS and frailty (OR [95%CI] = 1.6 to 4.5 [1.21 to 5.79]) for all equations with the exception of Smith's equations for frailty in women. All the equations presented adequate criterion validity, however, the Alcazar's equation showed the highest level of clinical relevance according to its ability to identify older people with frailty and low HGS. •Muscle power values differed between equations.•Power values estimated from all equations were related to gait speed and frailty.•Alcazar's equation showed the highest level of clinical relevance

Functional Significance of the Interaction between the mRNA-binding Protein, Nab2, and the Nuclear Pore-associated Protein, Mlp1, in mRNA Export*S⃞

Nuclear export of mRNA requires several key mRNA-binding proteins that recognize and remodel the mRNA and target it for export via interactions with the nuclear pore complex. In Saccharomyces cerevisiae, the shuttling heterogeneous nuclear ribonucleoprotein, Nab2, which is essential for mRNA export, specifically recognizes poly(A) RNA and binds to the nuclear pore-associated protein, myosin-like protein 1 (Mlp1), which functions in mRNA export and quality control. Specifically, the N-terminal domain of Nab2 (Nab2-N; residues 1–97) interacts directly with the C-terminal globular domain of Mlp1 (CT-Mlp1: residues 1490–1875). Recent structural and binding studies focused on Nab2-N have shown that Nab2-N contains a hydrophobic patch centered on Phe73 that is critical for interaction with Mlp1. Engineered amino acid changes within this patch disrupt the Nab2/Mlp1 interaction in vitro. Given the importance of Nab2 and Mlp1 to mRNA export, we have examined the Nab2/Mlp1 interaction in greater detail and analyzed the functional consequences of disrupting the interaction in vivo. We find that the Nab2-binding domain of Mlp1 (Mlp1-NBD) maps to a 183-residue region (residues 1586–1768) within CT-Mlp1, binds directly to Nab2 with micromolar affinity, and confers nuclear accumulation of poly(A) RNA. Furthermore, we show that cells expressing a Nab2 F73D mutant that cannot interact with Mlp1 exhibit nuclear accumulation of poly(A) RNA and that this nab2 F73D mutant genetically interacts with alleles of two essential mRNA export genes, MEX67 and YRA1. These data provide in vivo evidence for a model of mRNA export in which Nab2 is important for targeting mRNAs to the nuclear pore for export