High prevalence of familial defective apolipoprotein B-100 in Switzerland

Familial defective apolipoprotein B-100 (FDB) is caused by a single G-to-A substitution at nucleotide 10,708 leading to an arginine to glutamine change at amino acid 3,500 of the apolipoprotein B-100 and thus, a reduced binding of the apolipoprotein B to the low density lipoprotein (LDL) receptor. In the present study, the prevalence of FDB in Switzerland was estimated, on the one hand, from a sample of 728 healthy volunteers whose origin was spread out over the entire German, French, and Romansh speaking parts of the country, and, on the other hand, from 142 unrelated Swiss families with primary hypercholesterolemia comprising 520 individuals. Using polymerase chain reaction (PCR)-based methods, three individuals were identified with the point mutation in the sample of volunteers, equivalent to a prevalence of approximately 1/240 (90% confidence interval: 1.51 x 10(-3)-1.03 x 10(-2)). The frequency of FDB in the sample of hypercholesterolemic subjects was 7/142, yielding a prevalence of approximately 1/190 extrapolated to the general population (90% confidence interval: 2.63 x 10(-3)-9.17 x 10(-2)). The combined prevalence based on both samples was 1/209. Thus, the investigated point mutation was highly prevalent in Switzerland and appeared to be more frequent than in other populations studied hitherto. Furthermore, the presence of the mutation was not necessarily associated with an elevation of serum cholesterol levels, particularly in young individuals. While in the non-affected volunteers cholesterol levels increased between the age of 19 and 23 years by 0.22 mmol/l or by 5.6% (P = 0.001), this phenomenon was even more pronounced in individuals with FDB. The three volunteers with the point mutation demonstrated an increase in total cholesterol concentrations by 1.30 mmol/l or by 25% within 2 years, suggesting that, in the early twenties, cholesterol concentrations increase markedly from normal to elevated levels. Considering the estimated high prevalence the relative ease of PCR-based tests, screening for FDB may become a standard procedure in patients with suggested familial forms of hypercholesterolemia

Fracture of aluminium reinforced with densely packed ceramic particles: influence of matrix hardening

Al-Cu matrix composites with a high volume fraction of alumina particles (41-62%) prepared by gas-pressure infiltration are characterized in tension and chevron-notch fracture testing before and after heat-treatment. Their mechanical behaviour is shown to depend markedly on the matrix structure and flow stress, and also on the nature and size of the reinforcement particles. Al-Cu matrix composites free of coarse Al2Cu matrix intermetallics and reinforced with 60 vol% high-strength polygonal alumina particles exhibit strength/toughness combinations that are in the same range as unreinforced high-strength aluminium alloys: the strength of the composites can be increased without decreasing their toughness. The results are interpreted on the basis of current cohesive zone models for crack propagation by microcavitation in elastic-plastic materials. (C) 2004 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Fax from Julio A. Baez to M. Cherif Bassiouni, Subject: Your telefax dated 16 June 1993

Fax from Julio A. Baez to M. Cherif Bassiouni, Subject: Your telefax dated 16 June 1993, enclosing letter from Philippe Miserez to Julio Baez dated 19 May 1993 and the list of prisons regularly visited by the International Committee of the Red Crosshttps://scholarlycommons.law.case.edu/documents_780/1031/thumbnail.jp

Interplay between interfacial energy, contact mechanics, and capillary forces in EGaIn droplets

Eutectic gallium–indium (EGaIn) is increasingly employed as an interfacial conductor material in molecular electronics and wearable healthcare devices owing to its ability to be shaped at room temperature, conductivity, and mechanical stability. Despite this emerging usage, the mechanical and physical mechanisms governing EGaIn interactions with surrounding objects─mainly regulated by surface tension and interfacial adhesion─remain poorly understood. Here, using depth-sensing nanoindentation (DSN) on pristine EGaIn/GaOx surfaces, we uncover how changes in EGaIn/substrate interfacial energies regulate the adhesive and contact mechanic behaviors, notably the evolution of EGaIn capillary bridges with distinct capillary geometries and pressures. Varying the interfacial energy by subjecting EGaIn to different chemical environments and by functionalizing the tip with chemically distinct self-assembled monolayers (SAMs), we show that the adhesion forces between EGaIn and the solid substrate can be increased by up to 2 orders of magnitude, resulting in about a 60-fold increase in the elongation of capillary bridges. Our data reveal that by deploying molecular junctions with SAMs of different terminal groups, the trends of charge transport rates, the resistance of monolayers, and the contact interactions between EGaIn and monolayers from electrical characterizations are governed by the interfacial energies as well. This study provides a key understanding into the role of interfacial energy on geometrical characteristics of EGaIn capillary bridges, offering insights toward the fabrication of EGaIn junctions in a controlled fashion

Sediment yield at southwest Ethiopia's forest frontier

Deforestation is one of the major factors affecting soil erosion in tropical regions but to what extent does the crop growth in deforested areas protect the land from erosion? We evaluated the effect of deforestation on suspended sediment yield at the scale of zero-order catchments by contrasting five paired small forest and cropland catchments at Ethiopia's southwestern forest frontier. Suspended sediment samples were collected from nine San Dimas flumes and one V-notch weir installed in catchments draining the natural forest and cropland, at different altitudes. The suspended sediment data were collected from June 8 to October 30, 2013 and 2014. The suspended sediment yield of both land-use types was strongly correlated with the corresponding runoff discharge. The results show that the average seasonal suspended sediment yield from cropland (17.0 +/- 7.6 Mg ha(-1)) is four times higher than from the paired forests (4.0 +/- 1.9 Mg ha(-1)). High sediment yields from forests are related to livestock grazing, but forests still have an important role in the protection of the surface soil from erosion at southwest Ethiopia's forest frontier. Land management in southwestern Ethiopia's highlands will need a strong change in paradigm, in which the overall belief in the recently imported mahrasha ard plough is abandoned, oxen and other cattle decreased in number and kept in homesteads, the forests being protected from human and livestock interferences and the open farmlands turned into agroforestry. Such an approach is still possible as all required elements are available in the landscape

Crystal orientation mapping and microindentation reveal anisotropy in Porites skeletons

Structures made by scleractinian corals support diverse ocean ecosystems. Despite the importance of coral skeletons and their predicted vulnerability to climate change, few studies have examined the mechanical and crystallographic properties of coral skeletons at the micro- and nano-scales. Here, we investigated the interplay of crystallographic and microarchitectural organization with mechanical anisotropy within Porites skeletons by measuring Young’s modulus and hardness along surfaces transverse and longitudinal to the primary coral growth direction. We observed micro-scale anisotropy, where the transverse surface had greater Young’s modulus and hardness by ∼ 6 GPa and 0.2 GPa, respectively. Electron backscatter diffraction (EBSD) revealed that this surface also had a higher percentage of crystals oriented with the a-axis between ± 30-60∘, relative to the longitudinal surface, and a broader grain size distribution. Within a region containing a sharp microscale gradient in Young’s modulus, nanoscale indentation mapping, energy dispersive spectroscopy (EDS), EBSD, and Raman crystallography were performed. A correlative trend showed higher Young’s modulus and hardness in regions with individual crystal bases (c-axis) facing upward, and in crystal fibers relative to centers of calcification. These relationships highlight the difference in mechanical properties between scales (i.e. crystals, crystal bundles, grains). Observations of crystal orientation and mechanical properties suggest that anisotropy is driven by microscale organization and crystal packing, rather than intrinsic crystal anisotropy. In comparison with previous observations of nanoscale isotropy in corals, our results illustrate the role of hierarchical architecture in coral skeletons and the influence of biotic and abiotic factors on mechanical properties at different scales