A contact lens with built-in display: science fiction or not?

Recent progress in microsystems integration technology such as ultra-thin chip packaging, stretchable interconnections, thin-film batteries and organic photovoltaics makes it feasible to incorporate various electronic components and transducers in extremely confined spaces and inside flexible or conformable objects. Can this ultimately lead to a genuine display in a contact lens? The major outstanding issues are reviewed

Practical aspects of modelling parameter uncertainty for risk capital calculation

“This is a post-peer-review, pre-copyedit version of an article published in Zeitschrift fur die gesamte Versicherungswissenschaft. The final authenticated version is available online at: http://dx.doi.org/10.1007/s12297-019-00428-xWe assume that an insurance undertaking models its risk by a random variable X=X(¿0) with a fixed parameter (vector) ¿0. If the undertaking does not know ¿0 and can only estimate it from historical data, it faces parameter uncertainty. Neglecting parameter uncertainty can lead to an underestimation of the true risk capital requirement (see e.g. Gerrard and Tsanakas 2011; Fröhlich and Weng 2015). In this contribution we address some practical questions. To illustrate the relevance of the parameter risk we determine the probability of solvency for a risk capital model not taking parameter uncertainty into account for different distributions and samples sizes. We then follow the “inversion method” introduced in Fröhlich and Weng (2015) known to model an appropriate risk capital requirement respecting parameter uncertainty for a wide class of distributions and common estimation methods. We extend the idea to distribution families and estimation methods that have not been considered so far in this context but are frequently used to model the losses of an insurance undertakingPeer ReviewedPostprint (author's final draft

Evolution of Ego-networks in Social Media with Link Recommendations

Ego-networks are fundamental structures in social graphs, yet the process of their evolution is still widely unexplored. In an online context, a key question is how link recommender systems may skew the growth of these networks, possibly restraining diversity. To shed light on this matter, we analyze the complete temporal evolution of 170M ego-networks extracted from Flickr and Tumblr, comparing links that are created spontaneously with those that have been algorithmically recommended. We find that the evolution of ego-networks is bursty, community-driven, and characterized by subsequent phases of explosive diameter increase, slight shrinking, and stabilization. Recommendations favor popular and well-connected nodes, limiting the diameter expansion. With a matching experiment aimed at detecting causal relationships from observational data, we find that the bias introduced by the recommendations fosters global diversity in the process of neighbor selection. Last, with two link prediction experiments, we show how insights from our analysis can be used to improve the effectiveness of social recommender systems.Comment: Proceedings of the 10th ACM International Conference on Web Search and Data Mining (WSDM 2017), Cambridge, UK. 10 pages, 16 figures, 1 tabl

Search for ADD Direct Graviton Emission in Photon plus Missing Transverse Energy Final State at CMS

The exclusive gamma and met signature is used as a probe for the discovery reach of ADD large extra dimensions at the CMS detector. Signal samples for various model parameters as well as possible backgrounds have beensimulated partially using the CMS fast detector simulation. The reconstruction performance and efficiency obtained with the fast simulation has been compared with the detailed full simulation. A normalisation method is proposed to measure the main background Z (rightarrow nunubar) +gamma with high precision using reference spectra from Z (rightarrow mu^+mu^-) + gamma and Z (rightarrow e^+ e^-) + gamma. The discovery reach at the LHC with CMS is presented and the potential to determine parameters of the underlying model is discussed

Physico-chemical and thermochemical studies of the hydrolytic conversion of amorphous tricalcium phosphate into apatite

The conversion of amorphous tricalcium phosphate with different hydration ratio into apatite in water at 25 °C has been studied by microcalorimetry and several physical–chemical methods. The hydrolytic transformation was dominated by two strong exothermic events. A fast, relatively weak, wetting process and a very slow but strong heat release assigned to a slow internal rehydration and the crystallization of the amorphous phase into an apatite. The exothermic phenomenon related to the rehydration exceeded the crystalline transformation enthalpy. Rehydration occurred before the conversion of the amorphous phase into apatite and determined the advancement of the hydrolytic reaction. The apatitic phases formed evolved slightly with time after their formation. The crystallinity increased whereas the amount of HPO4 2− ion decreased. These data allow a better understanding of the behavior of biomaterials involving amorphous phases such as hydroxyapatite plasma-sprayed coating

CARMA1 is a novel regulator of T-ALL disease and leukemic cell migration to the CNS

No abstract available

CFD modelling of a two-phase closed thermosyphon charged with R134a and R404a

This paper examines the application of CFD modelling to simulate the two-phase heat transfer mechanisms in a wickless heat pipe, also called a thermosyphon. Two refrigerants, R134a and R404a, were selected as the working fluids of the investigated thermosyphon. A CFD model was built to simulate the details of the two-phase flow and heat transfer phenomena during the start-up and steady-state operation of the thermosyphon. The CFD simulation results were compared with experimental measurements, with good agreement obtained between predicted temperature profiles and experimental temperature data, thus confirming that the CFD model was successful in reproducing the heat and mass transfer processes in the R134a and R404a charged thermosyphon, including the pool boiling in the evaporator section and the liquid film in the condenser section

The Pion in Electromagnetic and Weak Neutral Current Nuclear Response Functions

The impact of pionic correlations and meson--exchange currents in determining the (vector) response functions for electroweak quasielastic lepton scattering from nuclei is discussed. The approach taken builds on previous work where the Fermi gas model is used to maintain consistency in treating forces and currents (gauge invariance) and to provide a Lorentz covariant framework. Results obtained in first-order perturbation theory are compared with infinite-order summation schemes (HF and RPA) and found to provide quite successful approximations for the quasielastic response functions. The role of pionic correlations in hardening the responses R_L and R_T is investigated in some detail, including studies of the relative importance of central and tensor pieces of the force and of exchange and self-energy diagrams; in addition, their role in significantly modifying the longitudinal parity-violating response R_{AV}^L is explored. The MEC are shown to provide a small, but non-negligible, contribution in determining the vector responses.Comment: TeX, 21 figures (Postscript, available from the authors), MIT preprint CTP\#219

Comparative study of collagen and gelatin coatings on titanium surfaces

The vast majority of studies in the bone tissue engineering field are focused on the surface modification of titanium scaffolds to obtain integration of the scaffold in the surrounding bone tissue. Our approach consisted in benefiting from the advantages of the cell-interaction capabilities of collagen and gelatin. The biopolymers were immobilised onto the Ti surface through different methods and the stability of the obtained coatings was determined. The obtained results reveal that covalent immobilisation of collagen and gelatin is required to obtain stable surface coatings