Rare-earth free sensitizer in NaLuCrF4:Er upconversion material

Upconversion phosphors are known as a material system that can convert near-infrared light into visible/ultraviolet emissions by sequentially absorbing multiple photons. The studies on upconversion materials often use two rare earth (RE) ions as a sensitizer-activator pair. We investigated the influences on luminescence intensity depending on Cr-doping content (x) of hexagonal NaLu_0.98–xCr_xF₄Er_0.02 (x = 0–0.9) upconversion material by substituting Lu³⁺ ions with Cr³⁺in the absence of Gd³⁺. The change in upconversion luminescence intensity appears with saddle-like shape. We suggest that Cr³⁺ ions play the dual role as a constituent in host lattice and a sensitizer in the upconversion process. Optimal conditions for gaining the strongest upconversion emission correspond to x = 0.3–0.5, where there are effective energy transfers between Cr³⁺ and Er³⁺ ions and CrEr dimers. Apart from these values, the emission intensity decreases rapidly which can be ascribed to the absence of multiple-photon absorption for the case of low Cr³⁺ contents, and to the coupling between Cr³⁺ and/or Er³⁺ ions for the case of high Cr³⁺ contents. Magnetization and electron-spin-resonant measurements were performed to understand the correlation between the optical and magnetic properties.     

Pull-Down of Metalloproteins in Their Native States by Using Desthiobiotin-Based Probes

One-third of all proteins are estimated to require metals for structural stability and/or catalytic activity. Desthiobiotin probes containing metal binding groups can be used to capture metalloproteins with exposed active-site metals under mild conditions so as to prevent changes in metallation state. The proof-of-concept was demonstrated with carbonic anhydrase (CA), an open active site, Zn²⁺-containing protein. CA was targeted by using sulfonamide derivatives. Linkers of various lengths and structures were screened to determine the optimal structure for capture of the native protein. The optimized probes could selectively pull down CA from red blood cell lysate and other protein mixtures. Pull-down of differently metallated CAs was also investigated.     

Negation as failure for disjunctive logic programming

We generalize the Negation-as-Failure procedure for disjunctive logic programming. Then we compare our method with related methods in the literature. We also propose a new completion theory for disjunctive logic programs which allows some program clauses to have inclusive meaning and the others exclusive meaning.     

On the SEP of Cooperative Diversity with Opportunistic Relaying

We analyze the exact symbol error probability (SEP) of cooperative diversity with opportunistic amplify-and-forward (AF) relaying. The benefit of this opportunism to the SEP is assessed by comparing with maximal ratio combining of orthogonal multiple AF relay transmissions.     

Simulating a Smartboard by Real-Time Gesture Detection in Lecture Videos

Gesture plays an important role for recognizing lecture activities in video content analysis. In this paper, we propose a real-time gesture detection algorithm by integrating cues from visual, speech and electronic slides. In contrast to the conventional “complete gesture” recognition, we emphasize detection by the prediction from “incomplete gesture”. Specifically, intentional gestures are predicted by the modified hidden Markov model (HMM) which can recognize incomplete gestures before the whole gesture paths are observed. The multimodal correspondence between speech and gesture is exploited to increase the accuracy and responsiveness of gesture detection. In lecture presentation, this algorithm enables the on-the-fly editing of lecture slides by simulating appropriate camera motion to highlight the intention and flow of lecturing. We develop a real-time application, namely simulated smartboard, and demonstrate the feasibility of our prediction algorithm using hand gesture and laser pen with simple setup without involving expensive hardware.      

Coaggregation of oral lactobacilli with streptococci from the oral cavity

The ability of oral lactobacilli to coaggregate with streptococci and actinomycetes was investigated. Of the 7 species of lactobacilli studied, only two were capable of coaggregation and the coaggregation was restricted to streptococci. Lactobacillus salivarius strains (2/4) coaggregated with Streptococcus salivarius, Streptococcus gordonii, Streptococcus crista and tufted Streptococcus sanguis II strains. Lactobacillus fermentum (2/3) coaggregated with S. gordonii and S. sanguis. The coaggregation between L. salivarius and S. salivarius, S. gordonii or tufted S. sanguis II strains was mediated by a protein on the surface of the lactobacilli and was not inhibited by lactose. The coaggregation between L. fermentum and the streptococci was mediated by protein on the surface of the streptococci and was inhibited by lactose.     

A Hammerstein-based dynamic model for hysteresis phenomenon

The Hammerstein configuration, which includes a nonlinear static block followed by a linear dynamic block, is applied to model the rate-dependent and temperature-dependent hysteresis phenomenon. The nonlinear static block is realized by a modified Preisach model, which includes both the irreversible and reversible components of magnetization. The linear dynamic block is realized by a low-pass filter, which takes into account the rate-dependent effects of hysteresis. Temperature dependencies are incorporated into the model by fitting the model parameters as piecewise-linear functions of temperature. A procedure is described for the extraction of a single set of model parameters over the frequency, amplitude, and temperature ranges of interest. The theory is verified experimentally     

Fertilization in vitro. A review over the medical indications and suggestion to unified guidelines for public fertility clinics in Denmark

Medical indications for in vitro fertilization and embryo transfer (IVF-ET) internationally and in Denmark are reviewed. Reports from large international centres document that tubal infertility, unexplained infertility, endometriosis and male infertility are equally good indications for IVF. Traditionally, tubal infertility has been the only medical indication qualifying for IVF treatment within the National Health Service in Denmark. Thus, in this country, couples with unexplained and male infertility and with endometriosis have to pay up to 25,000 D.Kr. per IVF-ET treatment in private fertility clinics. Since there is no scientific basis for this discrimination, it is urged that the present rules are changed, so that couples with unexplained and male infertility and endometriosis are also allowed IVF treatment free of charge in the public fertility clinics.