The N-glycome of human embryonic stem cells

<p>Abstract</p> <p>Background</p> <p>Complex carbohydrate structures, glycans, are essential components of glycoproteins, glycolipids, and proteoglycans. While individual glycan structures including the SSEA and Tra antigens are already used to define undifferentiated human embryonic stem cells (hESC), the whole spectrum of stem cell glycans has remained unknown. We undertook a global study of the asparagine-linked glycoprotein glycans (N-glycans) of hESC and their differentiated progeny using MALDI-TOF mass spectrometric and NMR spectroscopic profiling. Structural analyses were performed by specific glycosidase enzymes and mass spectrometric fragmentation analyses.</p> <p>Results</p> <p>The data demonstrated that hESC have a characteristic N-glycome which consists of both a constant part and a variable part that changes during hESC differentiation. hESC-associated N-glycans were downregulated and new structures emerged in the differentiated cells. Previously mouse embryonic stem cells have been associated with complex fucosylation by use of SSEA-1 antibody. In the present study we found that complex fucosylation was the most characteristic glycosylation feature also in undifferentiated hESC. The most abundant complex fucosylated structures were Le^xand H type 2 antennae in sialylated complex-type N-glycans.</p> <p>Conclusion</p> <p>The N-glycan phenotype of hESC was shown to reflect their differentiation stage. During differentiation, hESC-associated N-glycan features were replaced by differentiated cell-associated structures. The results indicated that hESC differentiation stage can be determined by direct analysis of the N-glycan profile. These results provide the first overview of the N-glycan profile of hESC and form the basis for future strategies to target stem cell glycans.</p

Locus of emotion influences psychophysiological reactions to music

It is now widely accepted that the perception of emotional expression in music can be vastly different from the feelings evoked by it. However, less understood is how the locus of emotion affects the experience of music, that is how the act of perceiving the emotion in music compares with the act of assessing the emotion induced in the listener by the music. In the current study, we compared these two emotion loci based on the psychophysiological response of 40 participants listening to 32 musical excerpts taken from movie soundtracks. Facial electromyography, skin conductance, respiration and heart rate were continuously measured while participants were required to assess either the emotion expressed by, or the emotion they felt in response to the music. Using linear mixed effects models, we found a higher mean response in psychophysiological measures for the “perceived” than the “felt” task. This result suggested that the focus on one’s self distracts from the music, leading to weaker bodily reactions during the “felt” task. In contrast, paying attention to the expression of the music and consequently to changes in timbre, loudness and harmonic progression enhances bodily reactions. This study has methodological implications for emotion induction research using psychophysiology and the conceptualization of emotion loci. Firstly, different tasks can elicit different psychophysiological responses to the same stimulus and secondly, both tasks elicit bodily responses to music. The latter finding questions the possibility of a listener taking on a purely cognitive mode when evaluating emotion expression

Screening ethnically diverse human embryonic stem cells identifies a chromosome 20 minimal amplicon conferring growth advantage

The International Stem Cell Initiative analyzed 125 human embryonic stem (ES) cell lines and 11 induced pluripotent stem (iPS) cell lines, from 38 laboratories worldwide, for genetic changes occurring during culture. Most lines were analyzed at an early and late passage. Single-nucleotide polymorphism (SNP) analysis revealed that they included representatives of most major ethnic groups. Most lines remained karyotypically normal, but there was a progressive tendency to acquire changes on prolonged culture, commonly affecting chromosomes 1, 12, 17 and 20. DNA methylation patterns changed haphazardly with no link to time in culture. Structural variants, determined from the SNP arrays, also appeared sporadically. No common variants related to culture were observed on chromosomes 1, 12 and 17, but a minimal amplicon in chromosome 20q11.21, including three genes expressed in human ES cells, ID1, BCL2L1 and HM13, occurred in >20% of the lines. Of these genes, BCL2L1 is a strong candidate for driving culture adaptation of ES cells

Plant communities of field boundaries in Finnish farmland

To determine the importance of field boundary habitats for farmland biodiversity, we surveyed a total of 193 boundaries from four climatically and agriculturally dissimilar regions in Finland. We measured the current plant species richness and composition of the boundaries, and based on the differences in vegetation characteristics, we describe six boundary types. The observed plant species were mainly indicators of fresh to wet soils and moderate to rich mineral nitrogen content. The most frequent species were tall, perennial monocots and dicots indicating the high productivity of thevegetation. Moreove, herbicide-tolerant species were common. No species rare for Finland were found.In animal husbandry regions, the most frequent species were sown grassland species and typical grassland weeds. In cereal production regions, fast-spreading root weeds tolerant of herbicides were the most frequent. Mean species richness was highest in the cluster Ca-lamagrostis-Phalaris (24 species (s)/boundary (b)), which we considered as representative of moist sites with some disturbance by agricultural practices. Most species-poor were the clusters Elymus-Anthriscus (14 s/b)and Elymus-Cirsium (16 s/b),both found predominantly in cereal production regions in southern Finland. Our results suggest that the biodiversity value of boundaries is lowest in the most intensive cereal production areas and highest in areas of mixed farming.

Borel* Sets in the Generalized Baire Space and Infinitary Languages

We start by giving a survey to the theory of Borel∗(κ) sets in the generalized Baire space Baire(κ)=κκ. In particular we look at the relation of this complexity class to other complexity classes which we denote by Borel(κ), Δ11(κ) and Σ11(κ) and the connections between Borel∗(κ) sets and the infinitely deep language Mκ+κ. In the end of the paper we will prove the consistency of Borel∗(κ)≠Σ11(κ).Peer reviewe

Behavioral predictors of quantitative ultrasound broadband attenuation score in young adult Caucasian women

Aim: Quantitative ultrasound (QUS) is frequently used to screen older individuals for bone fracture risk and to identify younger adults \u27with low bone quality. Current public health recommendations suggest that bone density and quality are related to being physically active, consuming sufficient amounts of calcium, and maintaining an appropriate body weight. This study examined the relationship of QUS broadband ultrasound attenuation (BUA) and speed of sound (SOS) measured at the calcaneus with behavioral and physical factors commonly associated with bone health. Methods: The study had a cross-sectional design. Ninety-eight Caucasian female university students 20-29 years of age were measured for height and weight, participated in QUS measurements of the calcaneus and completed questionnaires assessing health history, physical activity, calcium intake, and restrained eating. Results: Body weight explained 5% of the variance in BUA score (P\u3c0.05), but BUA was not associated with age, height, physical activity, calcium intake, restrained eating score, or use of oral contraceptives. Restrained eating score was positively related to subject weight (r=0.32, P\u3c0.01) and BMI (r=0.40, P\u3c0.01). The SOS score was not related to any of the physical or behavioral variables examined. Conclusion: In this group of young adult women, the attenuation of sound through bone was associated with body weight but not with behavioral factors commonly promoted to improve bone health. These findings question the advice commonly given to young women with low bone quality and suggest that other factors, including body weight, be considered