Ontogeny and Environment as Determinants of the Secondary Chemistry of Three Species of White Birch

This study investigates variation in the secondary chemistry of the bark of three closely related, winter-dormant species of white birch (Betula resinifera, B. pendula, and B. platyphylla) at different ontogenetic stages by using different plant parts (top and base). The experimental birches were grown for 4 years in two growing conditions (pot and field) at different nutrient levels. There was considerable species-specific quantitative and qualitative variation in the secondary chemicals in bark, but this was also affected by fertilization and the age of the plant. In general, there was greater chemical diversity in saplings than in seedlings. The study revealed three new components, secoisolariciresinol 9-O-β-glucopyranoside and two of its derivatives, that have not been reported previously for the bark of white birches. Principal component analysis showed that the species studied had a similar chemical composition at the juvenile stage, but as the plants grew, they became more clearly differentiated, which indicates that the species of older plants can be identified by chemotaxonomy. Evidently, the secondary chemistry of birches is under genetic control, but it is affected by properties of growing conditions and ontogeny. Electronic Supplementary Material Supplementary material to this paper is available in electronic form at     

Fluorescence-Based Nanoparticle Tracking Analysis and Flow Cytometry for Characterization of Endothelial Extracellular Vesicle Release

As extracellular vesicles (EVs) have become a prominent topic in life sciences, a growing number of studies are published on a regular basis addressing their biological relevance and possible applications. Nevertheless, the fundamental question of the true vesicular nature as well as possible influences on the EV secretion behavior have often been not adequately addressed. Furthermore, research regarding endothelial cell-derived EVs (EndoEVs) often focused on the large vesicular fractions comprising of microvesicles (MV) and apoptotic bodies. In this study we aimed to further extend the current knowledge of the influence of pre-isolation conditions, such as cell density and conditioning time, on EndoEV release from human umbilical vein endothelial cells (HUVECs). We combined fluorescence nanoparticle tracking analysis (NTA) and the established fluorescence-triggered flow cytometry (FT-FC) protocol to allow vesicle-specific detection and characterization of size and surface markers. We found significant effects of cell density and conditioning time on both abundance and size distribution of EndoEVs. Additionally, we present detailed information regarding the surface marker display on EVs from different fractions and size ranges. Our data provide crucial relevance for future projects aiming to elucidate EV secretion behavior of endothelial cells. Moreover, we show that the influence of different conditioning parameters on the nature of EndoEVs has to be considered.     

Optimism and Pessimism as Predictors of Change in Health After Death or Onset of Severe Illness in Family.

The authors prospectively examined changes in health after a major life event (death or onset of severe illness in family) among 5,007 employees (mean age=44.8 years) whose optimism and pessimism levels were assessed in 1997 and major life events in 2000. Health was indicated by sickness absence days during a period covering 36 months prior to the event and 18 months after the event. Increase in sick days after the event was smaller and returned to the preevent level more quickly among highly optimistic individuals than among their counterparts with low optimism. Parallel changes were not observed in relation to pessimism. These findings suggest that optimism may reduce the risk of health problems and may be related to a faster recovery after a major life event. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A europium chelate for quantitative point-of-care immunoassays using direct surface measurement

New labels and assay techniques are needed to improve the sensitivity and quantitativeness of point-of-care immunotesting while sustaining the rapidity and ease of use of the assays. We synthesized a novel, intrinsically fluorescent nonadentate europium chelate with two chromophores and hydrophilic alpha-galactose side groups. The chelate is highly fluorescent, soluble in water, and provides effective shielding of Eu from water. The performance of the nonadentate chelate was compared with a heptadentate chelate in a dry reagent immunoassay for human chorionic gonadotropin (hCG). After 15-min incubation and washing, time-resolved fluorescence was measured directly from a wet or dried well surface. Contrary to the heptadentate label, the effect of aqueous quenching on the nonadentate label was found to be insignificant, with calculated analytical detection limits (background + 3 SD) of 0.9 and 0.7 IU/L hCG for wet and dry measurements, respectively, and a linear range up to 5000 IU/L. The CVs for the new label were <8% at the cutoff of 25 IU/L and above in both whole blood and plasma. The novel nonadentate label facilitates short turnaround times and simple instrumentation due to the absence of all signal development steps, at the same time retaining an excellent immunoassay performance.     

Estimation of nonstationary EEG with Kalman smoother approach: an application to event-related synchronization (ERS)

An adaptive spectrum estimation method for nonstationary electroencephalogram by means of time-varying autoregressive moving average modeling is presented. The time-varying parameter estimation problem is solved by Kalman filtering along with a fixed-interval smoothing procedure. Kalman filter is an optimal filter in the mean square sense and it is a generalization of other adaptive filters such as recursive least squares or least mean square. Furthermore, by using the smoother the unavoidable tracking lag of adaptive filters can be avoided. Due to the properties of Kalman filter and benefits of the smoothing the time-frequency resolution of the presented Kalman smoother spectra is extremely high. The presented approach is applied to estimation of event-related synchronization/desynchronization (ERS/ERD) dynamics of occipital alpha rhythm measured from three healthy subjects. With the Kalman smoother approach detailed spectral information can be extracted from single ERS/ERD samples.     

Cre mRNA Is Not Transferred by EVs from Endothelial and Adipose-Derived Stromal/Stem Cells during Vascular Network Formation

Coculture systems employing adipose tissue-derived mesenchymal stromal/stem cells (ASC) and endothelial cells (EC) represent a widely used technique to model vascularization. Within this system, cell–cell communication is crucial for the achievement of functional vascular network formation. Extracellular vesicles (EVs) have recently emerged as key players in cell communication by transferring bioactive molecules between cells. In this study we aimed to address the role of EVs in ASC/EC cocultures by discriminating between cells, which have received functional EV cargo from cells that have not. Therefore, we employed the Cre-loxP system, which is based on donor cells expressing the Cre recombinase, whose mRNA was previously shown to be packaged into EVs and reporter cells containing a construct of floxed dsRed upstream of the eGFP coding sequence. The evaluation of Cre induced color switch in the reporter system via EVs indicated that there is no EV-mediated RNA transmission either between EC themselves or EC and ASC. However, since Cre mRNA was not found present in EVs, it remains unclear if Cre mRNA is generally not packaged into EVs or if EVs are not taken up by the utilized cell types. Our data indicate that this technique may not be applicable to evaluate EV-mediated cell-to-cell communication in an in vitro setting using EC and ASC. Further investigations will require a functional system showing efficient and specific loading of Cre mRNA or protein into EVs.     

A Case Study: Management and Exploitation of the Nuclear Decommissioning Agency Geoscience Data Archive

The British Geological Survey (BGS) is responsible for managing a major geoscience data archive on behalf of the UK Nuclear Decommissioning Authority (NDA). Much of this geological data was captured during the 1990s and early 2000s using now obsolete software and data formats. This data asset remains an important resource for the NDA and the wider scientific community. The NDA wishes to ensure the data remain accessible and usable for many decades into the future. BGS has been working closely with Radioactive Waste Management (RWM), a wholly owned subsidiary of the NDA, on a program of data management and digital continuity measures to ensure the long-term usability of the data. This article describes some of the challenges and outlines the approaches we have taken to address these issues.     

Kluyveromyces lactis SSO1 and SEB1 genes are functional in Saccharomyces cerevisiae and enhance production of secreted proteins when overexpressed

The SEB1/SBH1 and the SSO genes encode components of the protein secretory machinery functioning at the opposite ends, ER translocation and exocytosis, respectively, of the secretory pathway in Saccharomyces cerevisiae. Overexpression of these genes can rescue temperature-sensitive (ts) growth defect of many sec mutants impaired in protein secretion. Furthermore, their overexpression in wild-type yeast enhances production of secreted proteins in S. cerevisiae, which suggests that they may be rate-limiting factors in this process. Here we report isolation of Kluyveromyces lactis homologues of these genes. KlSSO1 and KlSEB1 were isolated as clones capable of rescuing growth of ts sso2-1 and seb1Delta seb2Delta sem1Delta strains, respectively, at the restrictive temperature. The encoded Kluyveromyces proteins are up to 70% identical with the S. cerevisiae homologues at the amino acid level and can functionally replace them. Interestingly, KlSSO1 and KlSEB1 show similar enhancing effect on production of a secreted protein as the SSO and SEB1 genes of S. cerevisiae when overexpressed. In accordance with the high homology level of the secretory pathway proteins in different yeast species, the polyclonal antibodies raised against S. cerevisiae Seb1p, Sso2p and Sec4p can detect homologous proteins in cell lysates of K. lactis and Pichia pastoris, the latter also in Candida utilis. The GenBank Accession Nos are AF307983 (K. lactis SSO1) and AF318314 (K. lactis SEB1).     

When It Is Better to Give Than to Receive: Long-Term Health Effects of Perceived Reciprocity in Support Exchange.

The authors examined esteem enhancement theory and equity theory in explaining the long-term health status of men (n = 178) and women (n = 575). Baseline characteristics were measured in 1990-1993, intimate reciprocity in 1993, and recorded sickness absences for a 9-year period during 1993-2001. Among women, giving more support than receiving in intimate relationships positively affected subsequent health status, as indicated by fewer sickness absences. Among men, receiving more support than giving predicted fewer absences. These effects remained even after significant covariates were included in the model. Thus, women seem to benefit from giving support in intimate relationships, and men seem to benefit from receiving support in intimate relationships. The findings on women are in line with the esteem enhancement theory. No support was obtained for the equity theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)