Electromagnetic and mechanical design aspects of a high-speed solid-rotor induction machine with no separate copper electric circuit in the megawatt range

The most crucial electro-magnetic and mechanical design aspects of an integrated electrical-motor–gas-compressor system in high speed and high power operation are presented. The electric motor type considered is a solid-rotor induction motor with properties of which are particularly well suited in high-speed operation. The effect of the electro-magnetic material properties of the solid rotor core material on the performance of the machine is discussed. Guidelines to improve the performance of the solid-rotor induction motor are given. Thermal design aspects of a solid-rotor induction motor are presented. The mechanical properties of a solid rotor are discussed. Bearing arrangements as well as the rotor dynamics of an integrated system are presented.     

High-performance real-time quantitative RT-PCR using lanthanide probes and a dual-temperature hybridization assay

We report a time-resolved fluorescence-based, homogeneous approach for multiplex, real-time or end-point detection of PCR products. Signal generation consists of PCR associated digestion of a 5'-labeled oligonucleotide probe, rapid cooling of the reaction mixture, and hybridization of undigested probe oligonucleotides with a complementary, shorter probe that incorporates a quencher at its 3' end. The signal coming from intact fluorescent probe molecules is, thus, quenched. The fluorophores we have used are environmentally sensitive lanthanide chelates. Their signals can be measured in a time-resolved manner that eliminates most of the unspecific fluorescent background. Signal-to-noise ratios are further enhanced by the environmental sensitivity of these chelates; they exhibit a higher fluorescence intensity when free in solution than when coupled to intact probe molecules. Because of the minimal background fluorescence, the signal-to-noise ratios are higher and threshold cycles are lower than those obtained using conventional TaqMan probes. The multiplexing capacity of the assay chemistry is demonstrated through simultaneous amplification and detection of prostate specific antigen (PSA) cDNA and an internal standard mRNA (mmPSA) using probes labeled with terbium and europium. The applicability of the assay chemistry to routine clinical diagnostics is demonstrated through absolute quantification of PSA mRNA in peripheral blood.     

Functional inactivation of the conserved Sem1p in yeast by intrabodies

Intrabody technology was applied to characterize the function and intracellular localization of a highly conserved Saccharomyces cerevisiae Sem1 protein. DSS1, the mammalian homologue of Sem1p, is functionally conserved between yeast and mammalian cells, and in mammalian cells physically interacts with the strong tumour supressor BRCA2. Yeast and the generated intrabodies are thus expected to offer a useful system for studies on Sem1p/DSS1 function. Sem1p-specific antibody isolated from a phage display library was expressed intracellularily and targeted to either the cytosol or the nucleus of yeast cells. Analysis of the applicability of different antibody fragments as intrabodies showed that the Fab intrabody was expressed most efficiently. Expression of nuclear-targeted anti-Sem1p Fab intrabodies inhibited the growth of the sigma1278b yeast strain in a manner similar to deletion of the SEM1 gene. This indicates that the Fab intrabodies interact in vivo with Sem1p and result in inactivation of Sem1p. Localization of the Fab intrabody with or without the nuclear localization signal to the nucleus in Sem1p-dependent manner suggests that Sem1p mediates the nuclear transport of the intrabody without any targeting signal. Our results suggest that Sem1p function in yeast cells is in part manifested in the nucleus.     

Embryo cryopreservation and transfer in Mustelidae: Approaches to ex situ conservation of the endangered European mink

Successful cryopreservation of Mustelidae embryos was proved by development of frozen–thawed farmed European polecat (model species) embryos both in vitro and in vivo. Intra- and interspecies embryo transfer was performed between the endangered European mink (Mustela lutreola) and related Mustelidae species: European polecats (Mustela putorius) and domestic ferrets (Mustela putorius furo). Intraspecies embryo transfer was successful if more than two embryos were transferred. However, straightforward interspecies embryo transfers between different Mustelidae species have not resulted in term kits. Nonetheless, this paper demonstrates the possibility to overcome interspecies pregnancy failure by using European polecat/European mink hybrid females (called honoriks or nohoriks) as recipients for European mink embryos. Integrated package of reproductive technologies, i.e. production of polecat/mink hybrids, cryopreservation and subsequent transfer of European mink embryos into uterine horns of hybrid females is recommended as an option for ex situ conservation of the European mink.     

Bioavailability of sediment-associated PCDD/Fs and PCDEs: relative importance of contaminant and sediment characteristics and biological factors

Factors that determine accumulation of sediment-associated polychlorinated dibenzo-p-dioxins and furans and polychlorinated diphenyl ethers into semipermeable membrane devices (SPMDs) and benthic oligochaete worms (Lumbriculus variegatus) were examined. These factors included both physical-chemical and structural characteristics of the contaminants (water solubility, lipophilicity, dipole moment, molecular size, and conformation) and sediment characteristics (organic carbon content, particle size, aromaticity, and polarity of organic carbon). The results of partial least squares regression analysis indicated that lipophilicity alone is not a sufficient predictor for contaminant bioaccumulation potential, even though it is a significant contributor. It was shown that contaminant molecular size and conformation (specifically planarity/nonplanarity) as well as sediment characteristics also have a significant role. The studied factors contributed up to 63-88% of the variation in accumulation data for SPMDs and 50-65% for oligochaetes. Comparison of (bio)accumulation factors (BAF28d for oligochaetes and AF28d for SPMDs) revealed that accumulation of contaminants in oligochaetes is largely influenced by biological factors (e.g., feeding habits), while the physical-chemical nature of the process is emphasized for SPMDs.     

Density estimation with stagewise optimization of the empirical risk

We consider multivariate density estimation with identically distributed observations. We study a density estimator which is a convex combination of functions in a dictionary and the convex combination is chosen by minimizing the L ₂ empirical risk in a stagewise manner. We derive the convergence rates of the estimator when the estimated density belongs to the L ₂ closure of the convex hull of a class of functions which satisfies entropy conditions. The L ₂ closure of a convex hull is a large non-parametric class but under suitable entropy conditions the convergence rates of the estimator do not depend on the dimension, and density estimation is feasible also in high dimensional cases. The variance of the estimator does not increase when the number of components of the estimator increases. Instead, we control the bias-variance trade-off by the choice of the dictionary from which the components are chosen. Editor: Nicolo Cesa-Bianchi     

Buddy tracking — efficient proximity detection among mobile friends

Global positioning systems (GPS) and mobile phone networks make it possible to track individual users with an increasing accuracy. It is natural to ask whether this information can be used to maintain social networks. In such a network each user wishes to be informed whenever one of a list of other users, called the user’s friends, appears in the user’s vicinity. In contrast to more traditional positioning based algorithms, the computation here depends not only on the user’s own position on a static map, but also on the dynamic position of the user’s friends. Hence it requires both communication and computation resources. The computation can be carried out either between the individual users in a peer-to-peer fashion or by centralized servers where computation and data can be collected at one central location. In the peer-to-peer model, a novel algorithm for minimizing the number of location update messages between pairs of friends is presented. We also present an efficient algorithm for the centralized model, based on region hierarchy and quadtrees. The paper provides an analysis of the two algorithms, compares them with a naive approach, and evaluates them on user motions generated by the IBM City Simulator system.     

The effect of an apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers on brachial artery flow-mediated vasodilatory function in volunteers with elevated blood pressure

Background

The primary aim of this study was to test the hypothesis that an orally ingested apple polyphenol extract rich in epicatechin and flavan-3-ol oligomers improves endothelium-dependent brachial artery flow-mediated vasodilatation (FMD) in volunteers with borderline hypertension. The secondary aim of the study was to test whether the investigational product would improve endothelium-independent nitrate-mediated vasodilatation (NMD).

Methods

This was a single centre, repeated-dose, double-blind, placebo-controlled, crossover study in 60 otherwise healthy subjects (26 men, 34 women; aged 40-65 years) with borderline hypertension (blood pressure 130-139/85-89 mmHg) or unmedicated mild hypertension (blood pressure 140-165/90-95 mmHg). The subjects were randomised to receive placebo or the apple polyphenol extract to provide a daily dose of 100 mg epicatechin for 4 weeks, followed by a four to five-week wash-out period, and then 4 weeks intake of the product that they did not receive during the first treatment period. FMD and NMD of the left brachial artery were investigated with ultrasonography at the start and end of both treatment periods, and the per cent increase of the arterial diameter (FMD% and NMD%) was calculated.

Results

With the apple extract treatment, a significant acute improvement was detected in the mean change of maximum FMD% at the first visit 1.16 (p = 0.04, 95% CI: 0.04; 2.28), last visit 1.37 (p = 0.02, 95% CI: 0.22; 2.52) and for both visits combined 1.29 (p < 0.01, 95% CI: 0.40; 2.18). However, such improvement was not statistically significant when apple extract was compared with placebo. The overall long-term effect of apple extract on FMD% was not different from placebo. No statistically significant differences between the apple extract and placebo treatments were observed for endothelium-independent NMD.

Conclusions

A significant acute improvement in maximum FMD% with apple extract administration was found. However, superiority of apple extract over placebo was not statistically significant in our study subjects with borderline hypertension or mild hypertension. The study raised no safety concerns regarding the daily administration of an apple polyphenol extract rich in epicatechin.

Trial registration

The trial is registered at http://clinicaltrials.gov (identifier: NCT01690676). Registered 25th May 2012.

     

Sleeping problems and health behaviors as mediators between organizational justice and health.

The aim of this longitudinal cohort study was to investigate whether sleeping problems and health behaviors (smoking, alcohol consumption, and sedentary lifestyle) mediate the association between organizational justice and employee health. Health indicators were minor psychiatric morbidity, as assessed by the General Health Questionnaire (U. Werneke, D. P. Goldberg, 1. Yalcin, & B. T. Ustun, 2000), and poor self-rated health status. The results of logistic regression analysis of data for 416 male and 3,357 female hospital employees working during the 1998-2000 period in 10 Finnish hospitals suggest that sleeping problems are one of the underlying factors causing the adverse health effects of low organizational justice at work. No support for a mediating role of health behaviors between low organizational justice and health problems was obtained. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structural and Functional Support by Left Atrial Appendage Transplant to the Left Ventricle after a Myocardial Infarction

The left atrial appendage (LAA) of the adult heart has been shown to contain cardiac and myeloid progenitor cells. The resident myeloid progenitor population expresses an array of pro-regenerative paracrine factors. Cardiac constructs have been shown to inhibit deleterious remodeling of the heart using physical support. Due to these aspects, LAA holds promise as a regenerative transplant. LAAs from adult mT/mG mice were transplanted to the recipient 129X1-SvJ mice simultaneously as myocardial infarction (MI) was performed. A decellularized LAA patch was implanted in the control group. Two weeks after MI, the LAA patch had integrated to the ventricular wall, and migrated cells were seen in the MI area. The cells had two main phenotypes: small F4/80+ cells and large troponin C+ cells. After follow-up at 8 weeks, the LAA patch remained viable, and the functional status of the heart improved. Cardiac echo demonstrated that, after 6 weeks, the mice in the LAA-patch-treated group showed an increasing and statistically significant improvement in cardiac performance when compared to the MI and MI + decellularized patch controls. Physical patch-support (LAA and decellularized LAA patch) had an equal effect on the inhibition of deleterious remodeling, but only the LAA patch inhibited the hypertrophic response. Our study demonstrates that the LAA transplantation has the potential for use as a treatment for myocardial infarction. This method can putatively combine cell therapy (regenerative effect) and physical support (inhibition of deleterious remodeling).