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.     

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).     

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.     

Bioavailability of organic pollutants in boreal waters with varying levels of dissolved organic material

Dissolved organic matter (DOM) in 20 surface waters in Eastern Finland were characterized to examine relationships between structural and compositional properties of DOM and partition coefficients (K_p) describing sorption of four model contaminants to DOM and the bioavailability of contaminants by Daphnia magna. The hydrophobic acids (HbA), hydrophobic neutrals (HbN) and hydrophilic (HI) fractions of DOM were separated by XAD-8 resin. The K_Ps were measured by equilibrium dialysis. Model contaminants were benzo(a)pyrene (BaP), naphthalene (NAPH), 3.3′,4.4′-tetrachlorobiphenyl (TCB) and dehydroabietic acid (DHAA).DOM concentrations varied from 2.0 to 38.3 mg org. C/l in the water series. The percentage of HbA and the aromaticity of DOM, as indicated by the absorptivity at 270 nm (A₂₇₀) and hydrogen/carbon ratio (H/C ratio), increased with increasing DOM concentration. Significant correlations were observed between K_P of BAP, A₂₇₀ and HbA content of the DOM from different sources. For the other contaminants similar kinds of relationships between K_ps and quality parameters of DOM could not be found.The bioavailability of model compounds was decreased by increasing DOM concentration in the water series. For all four model contaminants, measured bioconcentration factors (BCF) correlated well with the A₂₇₀ of a water and HbA content of the DOM. These results show that the total DOM concentration is an important factor controlling the bioavailability of xenobiotics in natural waters. Besides the quantity also the quality of DOM, like proportion of HbA, can contribute in bioavailability.     

Indigenous dadih lactic acid bacteria: cell-surface properties and interactions with pathogens

ABSTRACT:  Cell surface properties of dadih lactic acid bacteria strains were studied for adhesion to hydrocarbons (BATH) and aggregation abilities. Autoaggregation correlates with adhesion, which is a prerequisite for colonization and infection of the gastrointestinal tract by many pathogens, whereas coaggregation has been related to the ability to interact closely with pathogens. The results demonstrated significant differences in cell surface properties among the tested natural lactic acid bacteria food strains. Hydrophobicity increased when the cells were heat inactivated. All strains showed aggregation abilities with the pathogen strains tested, but the coaggregation properties were strain-specific. Our results indicate that the ability to autoaggregate, together with cell surface hydrophobicity and coaggregation abilities with pathogen strains, can be used for preliminary screening in order to identify potentially probiotic bacteria suitable for human or animal use. This study suggest the importance to identify and characterize bacterial cell-wall properties to understand their role in adhesion to hydrocarbons, autoaggregation and relation to coaggregation mechanisms, and also the relevance to future probiotic food development from natural strains.