Design specification for LACIE formatted dot cards in EOD-LARSYS

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Program documentation: As-built design specification for Generalized Linear Model Analysis Of Variance program (GLMAOV)

There are no author-identified significant results in this report

Fracture Propagation Driven by Fluid Outflow from a Low-permeability Aquifer

Deep saline aquifers are promising geological reservoirs for CO2 sequestration if they do not leak. The absence of leakage is provided by the caprock integrity. However, CO2 injection operations may change the geomechanical stresses and cause fracturing of the caprock. We present a model for the propagation of a fracture in the caprock driven by the outflow of fluid from a low-permeability aquifer. We show that to describe the fracture propagation, it is necessary to solve the pressure diffusion problem in the aquifer. We solve the problem numerically for the two-dimensional domain and show that, after a relatively short time, the solution is close to that of one-dimensional problem, which can be solved analytically. We use the relations derived in the hydraulic fracture literature to relate the the width of the fracture to its length and the flux into it, which allows us to obtain an analytical expression for the fracture length as a function of time. Using these results we predict the propagation of a hypothetical fracture at the In Salah CO2 injection site to be as fast as a typical hydraulic fracture. We also show that the hydrostatic and geostatic effects cause the increase of the driving force for the fracture propagation and, therefore, our solution serves as an estimate from below. Numerical estimates show that if a fracture appears, it is likely that it will become a pathway for CO2 leakage.Comment: 21 page

Zinc-induced self-association of complement C3b and Factor H: implications for inflammation and age-related macular degeneration.

The sub-retinal pigment epithelial deposits (sRPEds) that are a hallmark of age-related macular degeneration (AMD) contain both C3b and mM levels of zinc. C3 is the central protein of complement, while C3u is formed by the spontaneous hydrolysis of the thioester bridge in C3. During activation, C3 is cleaved to form active C3b, then C3b is inactivated by Factor I and Factor H to form the C3c and C3d fragments. The interaction of zinc with C3 was quantified using analytical ultracentrifugation and X-ray scattering. C3, C3u, and C3b associated strongly in >100 μM [Zn], while C3c and C3d showed weak association. With zinc, C3 forms soluble oligomers, while C3u and C3b precipitate. We conclude that the C3, C3u and C3b association with zinc depended on the relative positions of C3d and C3c in each protein. Computational predictions showed that putative weak zinc binding sites with different capacities exist in all five proteins, in agreement with experiment. Factor H forms large oligomers in >10 μM [Zn]. In distinction to C3b or Factor H alone, the solubility of the central C3b-Factor H complex was much reduced at 60 μM [Zn], and even more so at >100 μM [Zn]. The removal of the C3b-Factor H complex by zinc explains the reduced C3u/C3b inactivation rates by zinc. Zinc-induced precipitation may contribute to the initial development of sRPEds in the retina, as well as reducing the progression to advanced AMD in higher-risk patients

Metastable bound state of a pair of two-dimensional spatially separated electrons in anti-parallel magnetic fields

We propose a new mechanism for binding of two equally charged carriers in a double-layer system subjected by a magnetic field of a special form. A field configuration for which the magnetic fields in adjacent layers are equal in magnitude and opposite in direction is considered. In such a field an additional integral of motion - the momentum of the pair P arises. For the case when in one layer the carrier is in the zero (n=0) Landau level while in the other layer - in the first (n=1) Landau level the dependence of the energy of the pair on its momentum E(P} is found. This dependence turns out to be nonmonotonic one : a local maximum and a local minimum appears, indicating the emergence of a metastable bound state of two carrier with the same sign of electrical charge.Comment: 7 page

Adsorption-Induced Deformation in Nanopores: Unexpected Results Obtained by Molecular Simulations

International audienceThe adsorption of a fluid in a nanoporous material induces deformations of the solid. The saturating regime, where the solid is filled with liquid, generally exhibits a linear relationship between the liquid pressure and the solid strain. This provides an experimental way to measure the elastic moduli of the solid walls. For large pores, the strain is determined by the pressure of the liquid saturating the pores and the mechanical properties of the porous solid. What happens at the nanometric scale, where liquid/matrix interfacial effects dominate? We have performed molecular simulations of a simple Lennard-Jones fluid confined between deformable nanoplatelets. The simulations provide the deformation of the nanopore as a function of the liquid pressure, in a way similar to what is done experimentally. The results show unexpected interface effects, which could be relevant to experimental data analysis

Mesoamerican nephropathy: a narrative review

Mesoamerican nephropathy (MeN) also known as chronic kidney disease of unknown etiology (CKDu) is prevalent in agriculturally rich areas. The most widely accepted pathophysiological explanation for MeN is chronic dehydration caused by prolonged exposure to the sun. Other theories include oxidative stress, chronic inflammation, infection and tubulointerstitial fibrosis. The clinical presentation is quite vague and is diagnosed similar to CKD from any cause using blood, urine analysis and ultrasound. The study highlights the need for interdisciplinary cooperation among physicians, epidemiologists, toxicologists, and geneticists while identifying significant research gaps and future objectives. Occupational health related to agriculture is not emphasised enough especially in third world countries where a large chunk of population heavily depend on farming. To safeguard the population at risk, the significance of community-based initiatives, occupational health measures, and regulatory changes is emphasised

The solution structure of heparan sulfate differs from that of heparin: implications for function.

The highly sulfated polysaccharides heparin and heparan sulfate (HS) play key roles in the regulation of physiological and pathophysiological processes. Despite its importance, no molecular structures of free HS have been reported up to now. By combining analytical ultracentrifugation, small-angle X-ray scattering and constrained scattering modelling recently used for heparin, we have analysed the solution structures for eight purified HS fragments dp6 to dp24 corresponding to the predominantly unsulfated GlcA-GlcNAc domains of heparan sulfate. Unlike heparin, the sedimentation coefficient s20,w of HS dp6-dp24 showed a small rotor speed dependence, where similar s20,w values of 0.82 to 1.26 S (absorbance optics) and 1.05 to 1.34 S (interference optics) were determined. The corresponding X-ray scattering measurements of HS dp6-dp24 gave radii of gyration RG values from 1.03 nm to 2.82 nm, cross-sectional radii of gyration RXS values from 0.31 nm to 0.65 nm, and maximum lengths L from 3.0 nm to 10.0 nm. These data showed that HS has a longer and more bent structure than heparin. Constrained scattering modelling starting from 5,000-12,000 conformationally-randomised HS structures gave best fit dp6-dp24 molecular structures that were longer and more bent than their equivalents in heparin. Alternative fits were obtained for HS dp18 and dp24, indicating their higher bending and flexibility. We conclude that HS displays bent conformations that are significantly distinct from that for heparin. The difference is attributed to the different predominant monosaccharide sequence and reduced sulphation of HS, indicating that HS may interact differently with proteins compared to heparin

Effect of rate of pyrolysis on the textural properties of naturally-templated porous carbons from alginic acid

AbstractThe effect of pyrolysis rate on the properties of alginic acid-derived carbonaceous materials, termed Starbon®, was investigated. Thermal Gravimetry-IR was used to prepare porous carbons up to 800°C at several rates and highlighted increased CO2 production at higher pyrolysis rates. N2 porosimetry of the resultant carbons shows how pyrolysis rate affects both the mesopore structure and thus surface area and surface energy. Surface capacity of these carbons was analysed by methylene blue dye adsorption. In general, as the rate of pyrolysis increased, the mesopore content and adsorbent capacity decreased. It is considered here that the rapid production of volatiles at these higher rates causes structural collapse of the non-templated pore network. The work here demonstrates that pyrolysis rate is a key variable which needs to be controlled to maximise the textural properties of Starbon® required for adsorption applications