Stretch de-spin mechanism Patent

Stretch Yo-Yo mechanism for reducing initial spin rate of space vehicl

Regulation and competition in the distribution sector in Belgium

While being a key sector in all developed economies, retail trade does actually appear to be one of the reasons for Europe’s lagging behind in potential output growth. One of the reasons for this lag could be regulation. By determining conditions for market access and for carrying out a commercial activity, the regulatory framework may exert some influence on both economic performance and market structure and, ultimately, on the degree of competition. The article assesses the retail trade situation in Belgium along these lines. As far as possible, Belgium’s performance is compared with that of neighbouring countries and the findings are assessed by cross-matching the various sources of information available. First, evidence from international indicators (such as those regularly published by the OECD), as well as from a review of the main legislation governing retail trade in Belgium, tend to suggest that regulation in Belgium is relatively abundant and restrictive for this sector. Operating conditions in particular appear to be more regulated than in neighbouring countries. As regards the retail trade sector’s economic performance, it should be noted that, like most other economic sectors, the retailing business in Belgium still has a higher productivity rate than in the majority of other European countries and even the United States too. However, unlike trends noted in other branches of activity, this favourable position has been gradually eroded over the last ten years. It does actually seem that Belgium’s main problem lies in its inability to improve the efficiency of the production factors being used. However, looking more closely at the food retailing sub-sector, no striking anomalies are noted in the market structure and the degree of competition in Belgium. Even though the overall indicators point to some concentration at national level, local competition – assessed with an original approach applied to detailed data – appears to be quite strong; only a few sales outlets have a dominant position. Moreover, the non-specialised food retail sector has a growing number of big shops, as well as an increasing number of hard discounters and a larger share of generic brand products in traditional retail outlets. Using detailed consumption price data from CityData and Eurostat, this analysis throws up evidence that prices charged by the retail sector are higher in Belgium than in the three neighbouring countries and the euro area as a whole. There have also been signs of a recent deterioration in the differential between prices in Belgian supermarkets and prices charged by German and Dutch supermarkets in particular. Adverse developments in labour costs in Belgium and higher retail business margins can go some way to explaining the trend in price differentials compared to Germany, where hard discounters are more common. Then again, the sharp deterioration in the price differentials between Belgium and the Netherlands recorded in supermarkets can largely be explained by the price war that raged between the major Dutch retail groups from October 2003 to December 2006. Overall, it therefore appears that the actual influence of specific regulatory requirements for the retail trade on the efficiency of the sector, on the degree of competition and, ultimately, on consumer prices needs to be looked at very carefully. On the one hand, simplifying regulations in force in Belgium would no doubt break down the barriers to entry without necessarily impeding other policy objectives. On the other hand, the performance of the retail distribution sector must be examined taking account of the specific features of the economy, such as population density and cultural preferences.retail, regulation, market structure, pricing, productivity

Extraction of scattering lengths from final-state interactions

A recently proposed method based on dispersion theory, that allows to extract the scattering length of a hadronic two-body system from corresponding final-state interactions, is generalized to the situation where the Coulomb interaction is present. The steps required in a concrete practical application are discussed in detail. In addition a thorough examination of the accuracy of the proposed method is presented and a comparison is made with results achieved with other methods like the Jost-function approach based on the effective-range approximation. Deficiencies of the latter method are pointed out. The reliability of the dispersion theory method for extracting also the effective range is investigated.Comment: 16 pages, 6 figures, some corrections to text, to appear in Phys. Rev.

Effective range function below threshold

We demonstrate that the kernel of the Lippmann-Schwinger equation, associated with interactions consisting of a sum of the Coulomb plus a short range nuclear potential, below threshold becomes degenerate. Taking advantage of this fact, we present a simple method of calculating the effective range function for negative energies. This may be useful in practice since the effective range expansion extrapolated to threshold allows to extract low-energy scattering parameters: the Coulomb-modified scattering length and the effective range.Comment: 14 pages, 1 figur

Permanent Polymer Coating for in vivo MRI Visualization of Tissue Reinforcement Prostheses

The clinical advantage of MRI visualization of prostheses in soft tissue prolapses is very appealing as over 1?000?000 MRI-transparent synthetic meshes are implanted annually, and postoperative complications such as mesh shrinkage and migration are frequent. Here, the synthesis of a new material composed of a DTPA-Gd complex grafted onto a backbone of PMA via a covalent bond is described (DTPA-Gd-PMA). This new polymer is sprayed onto meshes and gives an MR signal for a long period without any significant release of Gd. In vitro cytocompatibility tests on fibroblasts show limited cytotoxicity. Microscopic investigations indicate that vital cells rapidly colonize the material. Finally, coated meshes implanted in rats are easily recognizable using an MR imaging system

The Translation Regulatory Subunit eIF3f Controls the Kinase-Dependent mTOR Signaling Required for Muscle Differentiation and Hypertrophy in Mouse

The mTORC1 pathway is required for both the terminal muscle differentiation and hypertrophy by controlling the mammalian translational machinery via phosphorylation of S6K1 and 4E-BP1. mTOR and S6K1 are connected by interacting with the eIF3 initiation complex. The regulatory subunit eIF3f plays a major role in muscle hypertrophy and is a key target that accounts for MAFbx function during atrophy. Here we present evidence that in MAFbx-induced atrophy the degradation of eIF3f suppresses S6K1 activation by mTOR, whereas an eIF3f mutant insensitive to MAFbx polyubiquitination maintained persistent phosphorylation of S6K1 and rpS6. During terminal muscle differentiation a conserved TOS motif in eIF3f connects mTOR/raptor complex, which phosphorylates S6K1 and regulates downstream effectors of mTOR and Cap-dependent translation initiation. Thus eIF3f plays a major role for proper activity of mTORC1 to regulate skeletal muscle size

X-ray Fluorescent Fe Kalpha Lines from Stellar Photospheres

X-ray spectra from stellar coronae are reprocessed by the underlying photosphere through scattering and photoionization events. While reprocessed X-ray spectra reaching a distant observer are at a flux level of only a few percent of that of the corona itself, characteristic lines formed by inner shell photoionization of some abundant elements can be significantly stronger. The emergent photospheric spectra are sensitive to the distance and location of the fluorescing radiation and can provide diagnostics of coronal geometry and abundance. Here we present Monte Carlo simulations of the photospheric Kalpha doublet arising from quasi-neutral Fe irradiated by a coronal X-ray source. Fluorescent line strengths have been computed as a function of the height of the radiation source, the temperature of the ionising X-ray spectrum, and the viewing angle. We also illustrate how the fluorescence efficiencies scale with the photospheric metallicity and the Fe abundance. Based on the results we make three comments: (1) fluorescent Fe lines seen from pre-main sequence stars mostly suggest flared disk geometries and/or super-solar disk Fe abundances; (2) the extreme ~1400 mA line observed from a flare on V1486 Ori can be explained entirely by X-ray fluorescence if the flare itself were partially eclipsed by the limb of the star; and (3) the fluorescent Fe line detected by Swift during a large flare on II Peg is consistent with X-ray excitation and does not require a collisional ionisation contribution. There is no convincing evidence supporting the energetically challenging explanation of electron impact excitation for observed stellar Fe Kalpha lines.Comment: 30 pages; accepted for publication in the Astrophysical Journa

Inhibition of Atrogin-1/MAFbx Mediated MyoD Proteolysis Prevents Skeletal Muscle Atrophy In Vivo

Ubiquitin ligase Atrogin1/Muscle Atrophy F-box (MAFbx) up-regulation is required for skeletal muscle atrophy but substrates and function during the atrophic process are poorly known. The transcription factor MyoD controls myogenic stem cell function and differentiation, and seems necessary to maintain the differentiated phenotype of adult fast skeletal muscle fibres. We previously showed that MAFbx mediates MyoD proteolysis in vitro. Here we present evidence that MAFbx targets MyoD for degradation in several models of skeletal muscle atrophy. In cultured myotubes undergoing atrophy, MAFbx expression increases, leading to a cytoplasmic-nuclear shuttling of MAFbx and a selective suppression of MyoD. Conversely, transfection of myotubes with sh-RNA-mediated MAFbx gene silencing (shRNAi) inhibited MyoD proteolysis linked to atrophy. Furthermore, overexpression of a mutant MyoDK133R lacking MAFbx-mediated ubiquitination prevents atrophy of mouse primary myotubes and skeletal muscle fibres in vivo. Regarding the complex role of MyoD in adult skeletal muscle plasticity and homeostasis, its rapid suppression by MAFbx seems to be a major event leading to skeletal muscle wasting. Our results point out MyoD as the second MAFbx skeletal muscle target by which powerful therapies could be developed