A potential nutraceutical from Leuconostoc mesenteroides B-742 (ATCC 13146); production and properties

There is an emerging market for functional oligosaccharides for use in foods. Currently, technology for the production of oligosaccharides is limited to extraction from plant sources, acid or enzymatic hydrolysis of polysaccharides or synthesis by transglycosylation reactions. Oligosaccharides also can be produced using a Leuconostoc fermentation and restricting the polymer size by the addition of maltose. Maltose limits the dextransucrase reaction, yielding high concentrations of a-glucooligosaccharides. Branched oligomers produced by this process were found to be readily catabolized by bifidobacteria and lactobacillus but were not readily utilized by either Salmonella sp., or E. coli, pointing toward their use in intestinal microflora modification. Branched a-glucooligosaccharides were non-competitive inhibitors of a-glucosidase (maltase), an enzyme required for starch or maltodextrin utilization

Energy Efficient Transmission over Space Shift Keying Modulated MIMO Channels

Energy-efficient communication using a class of spatial modulation (SM) that encodes the source information entirely in the antenna indices is considered in this paper. The energy-efficient modulation design is formulated as a convex optimization problem, where minimum achievable average symbol power consumption is derived with rate, performance, and hardware constraints. The theoretical result bounds any modulation scheme of this class, and encompasses the existing space shift keying (SSK), generalized SSK (GSSK), and Hamming code-aided SSK (HSSK) schemes as special cases. The theoretical optimum is achieved by the proposed practical energy-efficient HSSK (EE-HSSK) scheme that incorporates a novel use of the Hamming code and Huffman code techniques in the alphabet and bit-mapping designs. Experimental studies demonstrate that EE-HSSK significantly outperforms existing schemes in achieving near-optimal energy efficiency. An analytical exposition of key properties of the existing GSSK (including SSK) modulation that motivates a fundamental consideration for the proposed energy-efficient modulation design is also provided

REVISITING HYSTERESIS IN UNEMPLOYMENT FOR TEN EUROPEAN COUNTRIES: AN EMPIRICAL NOTE ON A MORE POWERFUL NONLINEAR (LOGISTIC) UNIT ROOT

In this empirical note we use a more powerful nonlinear (logistic) unit root test advanced by Leybourne et al. (1998) to investigate the hysteresis in unemployment for ten European countries for the period 1961-2003. The hypothesis is confirmed for all the European countries for which Leybourne et al.¡¯s (1998) nonlinear (logistic) unit root test is performed, except for Belgium and the UK.Hysteresis in Unemployment, European Countries, Logistic Unit Root Tests

Spectral Weights, d-wave Pairing Amplitudes, and Particle-hole Tunneling Asymmetry of a Strongly Correlated Superconductor

The spectral weights (SW's) for adding and removing an electron of the Gutzwiller projected d-wave superconducting (SC) state of the t-J-type models are studied numerically on finite lattices. Restrict to the uniform system but treat exactly the strong correlation between electrons, we show that the product of weights is equal to the pairing amplitude squared, same as in the weakly coupled case. In addition, we derive a rigorous relation of SW with doping in the electron doped system and obtain particle-hole asymmetry of the conductance-proportional quantity within the SC gap energy and, also, the anti-correlation between gap sizes and peak heights observed in tunneling spectroscopy on high Tc cuprates.Comment: 4 Revtex pages and 4 .eps figures. Published versio

Supply Chain Efficiency Analysis: A Theoretical Approach

We divide the supply chain into a central control system (CCS) case and a decentralized control system (DCS) case, and compare the supply chain efficiency with both the CCS case and the DCS case.  We find that the supply chain efficiency of a capital-intensive industry is better under the CCS case than under the DCS case.  Under the CCS case, the maximized supply chain efficiency can be reached by choosing either the lowest price that the upstream firm is willing to receive or the highest price that the downstream firm is willing to pay for intermediate goods

Use of Pseudo-observations in the Goodness-of-Fit Test for Gray\u27s Time-Varying Coefficients Model

Background The Cox proportional hazards (PH) regression model is the most common method to estimate underlying survival or failure probabilities and to estimate the effects of covariates on survival times. In Cox PH models, the regression coefficients are assumed constant over time. However, if covariate effects vary over time, alternative models which do not necessarily assume proportionality are needed. Method We proposed the Gray’s time-varying coefficient (TVC) method based on pseudo-observation. By using pseudo-observations, pseudo-residuals were calculated and plotted against the estimated survival rates at each of the nine selected time points, then were used to evaluate the goodness-of-fit of the Gray’s model. We applied this method to assess the fit for a model that predicts post-transplant survival probability among children who were under the age of 12 years, had end-stage liver disease, and underwent liver transplantation between January 2005 and June 2010. Result For Gray’s TVC model, through the first time point and the sixth time point, pseudo residual plots are around zero, while pseudo residual plots show slight departure at small values of estimated survival rate through the seventh time point and the ninth time point. Since the pseudo residual plots stay around zero at each time point without any significant departure or tendency, we can conclude that Gray’s model shows a good fit in estimating survival function at each time point. The results from this real liver transplantation data demonstrate that the final Gray’s model shows a good fit in estimating post-transplant survival. Conclusion When data violate the PH assumption, the Gray TVC model or an alternative should be used to obtain unbiased estimates on survival function and give correct inference on the relationship between potential covariates and survival. The proposed goodness-of-fit test offers a tool to investigate how well the model fits the data