Combined Earth and Rock Bearing Foundation - Hospital Humana Mexico City D.F.

This text describes the design and performance of a shallow spread footing foundation system for a large medical care facility in Mexico City. The project is unusual because the spread footings bear on a combination of basaltic lava and coarse sand fill containing angular lava fragments, the latter of which was densified using the dynamic deep compaction process. In the following narrative, the exploratory program is described, the geotechnical design and construction process is explained, and the inspection procedure for footings bearing on rock and soil is discussed. Further, the results of precise settlement monitoring for the structure are presented

Spatio-temporal patterns in a mechanical model for mesenchymal morphogenesis

We present an in-depth study of spatio-temporal patterns in a simplified version of a mechanical model for pattern formation in mesenchymal morphogenesis. We briefly motivate the derivation of the model and show how to choose realistic boundary conditions to make the system well-posed. We firstly consider one-dimensional patterns and carry out a nonlinear perturbation analysis for the case where the uniform steady state is linearly unstable to a single mode. In two-dimensions, we show that if the displacement field in the model is represented as a sum of orthogonal parts, then the model can be decomposed into two sub-models, only one of which is capable of generating pattern. We thus focus on this particular sub-model. We present a nonlinear analysis of spatio-temporal patterns exhibited by the sub-model on a square domain and discuss mode interaction. Our analysis shows that when a two-dimensional mode number admits two or more degenerate mode pairs, the solution of the full nonlinear system of partial differential equations is a mixed mode solution in which all the degenerate mode pairs are represented in a frequency locked oscillation

Fingerprinting the tertiary structure of electroadsorbed lysozyme at soft interfaces by electrostatic spray ionization mass spectrometry

Lysozyme can be electrochemically detected after adsorption at an electrified gel–water interface. Ex situ characterization by electrostatic spray ionization mass spectrometry provides insights into the interfacial detection mechanism by allowing changes to the tertiary structure of electroadsorbed lysozyme to be fingerprinted for the first time

Tanner Duality Between the Oldroyd–Maxwell and Grade-two Fluid Models

We prove an asymptotic relationship between the grade-two fluid model and a class of models for non-Newtonian fluids suggested by Oldroyd, including the upper-convected and lower-convected Maxwell models. This confirms an earlier observation of Tanner. We provide a new interpretation of the temporal instability of the grade-two fluid model for negative coefficients. Our techniques allow a simple proof of the convergence of the steady grade-two model to the Navier–Stokes model as $\alpha \rightarrow 0$ (under suitable conditions) in three dimensions. They also provide a proof of the convergence of the steady Oldroyd models to the Navier–Stokes model as their parameters tend to zero

Diagonal chromatographic selection of cysteinyl peptides modified with benzoquinones

The derivatization of cysteine-containing peptides with benzoquinone compounds is rapid, quantitative and specific in acidic media. The conversion of cysteines into hydrophobic benzoquinone-adducted residues in peptides is used here to alter the chromatographic properties of cysteinyl peptides during liquid chromatography separation. The benzoquinone derivatization is shown to allow the accurate selection of cysteine-containing peptides of bovine serum albumin tryptic digest by diagonal reversed-phase chromatography, which consists of one primary and a series of secondary identical liquid chromatographic separations, before and after a cysteinyl-targeted modification of the peptides by benzoquinone compounds

Tanner Duality Between the Oldroyd–Maxwell and Grade-two Fluid Models

We prove an asymptotic relationship between the grade-two fluid model and a class of models for non-Newtonian fluids suggested by Oldroyd, including the upper-convected and lower-convected Maxwell models. This confirms an earlier observation of Tanner. We provide a new interpretation of the temporal instability of the grade-two fluid model for negative coefficients. Our techniques allow a simple proof of the convergence of the steady grade-two model to the Navier–Stokes model as $\alpha \rightarrow 0$ (under suitable conditions) in three dimensions. They also provide a proof of the convergence of the steady Oldroyd models to the Navier–Stokes model as their parameters tend to zero

On the numerical approximation of p-biharmonic and ∞-biharmonic functions

In [KP16] (arXiv:1605.07880) the authors introduced a second-order variational problem in L∞. The associated equation, coined the ∞-Bilaplacian, is a \emph{third order} fully nonlinear PDE given by Δ2∞u:=(Δu)3|D(Δu)|2=0. In this work we build a numerical method aimed at quantifying the nature of solutions to this problem which we call ∞-Biharmonic functions. For fixed p we design a mixed finite element scheme for the pre-limiting equation, the p-Bilaplacian Δ2pu:=Δ(|Δu|p−2Δu)=0. We prove convergence of the numerical solution to the weak solution of Δ2pu=0 and show that we are able to pass to the limit p→∞. We perform various tests aimed at understanding the nature of solutions of Δ2∞u and in 1-d we prove convergence of our discretisation to an appropriate weak solution concept of this problem, that of -solutions

Probing Cysteine Reactivity in Proteins by Mass Spectrometric EC-Tagging

The on-line electrochemical tagging (EC-tagging) of cysteine residues in proteins during mass spectrometry is studied to probe the cysteine environment. Benzoquinone probes electrogenerated at a microspray electrode react with the thiol functions of the proteins within a microchannel and the products are analyzed by mass spectrometry. The fundamentals of the technique are discussed, with a focus on the kinetic aspects. The EC-tagging efficiency of the cysteine residues in proteins is used to probe their environment. Experiments with unmodified proteins and their chemically reduced forms highlight the strong effect of the cysteine site reactivity on the tagging efficiencies. This study highlights relevant parameters for such on-line electrochemical derivatization/MS detection strategies

Electrochemical Multi-Tagging of Cysteinyl Peptides during Microspray Mass Spectrometry: Numerical Simulation of Consecutive Reactions in a Microchannel

On-line electrogeneration of mass tags in a microspray emitter is used to quantify the number of cysteine groups in a given peptide. A finite-element simulation of the multi-step process yields the relative distribution and concentration of tags, untagged and tagged species in the microchannel before the spray event. The work focuses on the tagging of cysteine moieties in peptides or proteins by electrogenerated quinone mass probes. The main chemical parameters determining the kinetics of the labelling are assessed and discussed considering the microfluidic aspects of the process. The control of the tagging extent allows the simultaneous MS analysis of both the unmodified and modified peptide(s). The number of cysteine groups corresponds to the number of characteristic mass shifts observed from the unmodified peptide. The present theoretical work establishes the range of optimum conditions for the determination of the number of cysteine groups in peptides containing up to five cysteine groups