Cell-Free Phospholipid Biosynthesis by Gene-Encoded Enzymes Reconstituted in Liposomes.

The goal of bottom-up synthetic biology culminates in the assembly of an entire cell from separate biological building blocks. One major challenge resides in the in vitro production and implementation of complex genetic and metabolic pathways that can support essential cellular functions. Here, we show that phospholipid biosynthesis, a multiple-step process involved in cell membrane homeostasis, can be reconstituted starting from the genes encoding for all necessary proteins. A total of eight E. coli enzymes for acyl transfer and headgroup modifications were produced in a cell-free gene expression system and were co-translationally reconstituted in liposomes. Acyl-coenzyme A and glycerol-3-phosphate were used as canonical precursors to generate a variety of important bacterial lipids. Moreover, this study demonstrates that two-step acyl transfer can occur from enzymes synthesized inside vesicles. Besides clear implications for growth and potentially division of a synthetic cell, we postulate that gene-based lipid biosynthesis can become instrumental for ex vivo and protein purification-free production of natural and non-natural lipids.

Family, welfare state generosity and the vulnerability of older adults: A cross-national study.

The availability of family can be considered a protective factor for aging well. In this article, we examine to what extent the family situation of older people creates vulnerability with respect to their quality of life. Because not everyone is vulnerable to the same degree, we try to identify the conditions under which older people benefit more from having family resources. Based on the resources perspective, we argue that the impact of family resources on life satisfaction is stronger for older people with fewer resources at both the individual level (material, physical and non-familial social resources) and the country level (welfare state services targeted at older adults). To test our hypotheses we make use of the fourth wave of the European Values Study, and the MULTILINKS Social Policy Indicators database. In general our data offer support for the idea that the presence of intimate family ties (with partner and children) can be considered an important resource for achieving psychological well-being, whereas their absence or loss may act as a constraint. Our vulnerability argument is partly supported by the findings. Partner resources are more important for the life satisfaction of older people with a low education and health problems. Similarly, having children only improves the life-satisfaction of lower educated older adults. However, family resources are not more important for older people with fewer material resources or for older people living in countries with low services levels targeted at older adults.

The Public Acceptance of Voluntary Childlessness in the Netherlands: from 20 to 90 per cent in 30 years.

Within a relatively short period of 30 years, public acceptance of voluntary childlessness has increased enormously in the Netherlands. In this paper, we address two research questions, which we answer with data from 13 waves of the repeated cross-sectional survey Cultural Change in the Netherlands (CCN, 1965-1996). First, we investigate to what extent the increasing permissiveness is due to cohort replacement and to intra-cohort change. We find that between 1965 and 1980 the change is primarily due to intra-cohort (period) effects, whereas cohort replacement has become more important since 1980. Second, we address the question which social categories constitute the 10% of the population who do not accept voluntary childlessness. Church attendance-and not religiosity or religious socialization-turns out to be the most important factor. Low levels of income and education also negatively affect the acceptance of voluntary childless.

Parental education, children's performance and the transition to higher secondary education: trends in primary and secondary effects over five Dutch school cohorts (1965-99).

According to Boudon, social background affects educational transitions as a result of differences in children's academic performance (primary effects) and differences in transition probabilities given children's level of academic performance (secondary effects). This study addresses historical changes in both primary and secondary effects on the educational transition from primary school to higher secondary education in The Netherlands. In addition, it considers changes over time in the relative importance of these effects. The study compares five cohorts of Dutch pupils, specifically those enrolling in secondary education in 1965, 1977, 1989, 1993 and 1999, and it employs counterfactual analyses. The main findings are that secondary effects have been stable and primary effects have fluctuated to some extent. As a result, the proportion of the total effect of social background accounted for by primary effects has increased somewhat, from 53 per cent to 58 per cent.

Intermarriage and the risk of divorce in the Netherlands: the effects of differences in religion and in nationality, 1974-94.

A textbook hypothesis about divorce is that heterogamous marriages are more likely to end in divorce than homogamous marriages. We analyse vital statistics on the population of the Netherlands, which provide a unique and powerful opportunity to test this hypothesis. All marriages formed between 1974 and 1984 (nearly 1 million marriages) are traced in the divorce records and multivariate logistic regression models are used to analyse the effects on divorce of heterogamy in religion and national origin. Our analyses confirm the hypothesis for marriages that cross the Protestant-Catholic or the Jewish-Gentile boundary. Heterogamy effects are weaker for marriages involving Protestants or unaffiliated persons. Marriages between Dutch and other nationalities have a higher risk of divorce, the more so the greater the cultural differences between the two groups. Overall, the evidence supports the view that, in the Netherlands, new group boundaries are more difficult to cross than old group boundaries.

Innervation pattern of the gill arches and gills of the carp (Cyprinus carpio).

The innervation pattern of the respiratory gill arches of the carp (Cyprinus carpio) is described. The gill region is innervated by the branchial branches of the glossopharyngeal and vagal nerves. Each branchial nerve divides at the level of or just distal to the epibranchial ganglion into: 1) a pretrematic branch, 2) a dorsal pharyngeal branch, and 3) a posttrematic branch. The dorsal pharyngeal branch innervates the palatal organ in the roof of the buccal cavity. The pretrematic and posttrematic branches innervate the posterior and anterior halves, respectively, of the gill arches bordering a gill slit. Each branch splits into an internal and an external part. The internal bundle innervates the buccal side of the gill arch, including the gill rakers. The external bundle terminates in the gill filaments. The epibranchial motor branch, a small nerve bundle containing only motor fibers, circumvents the ganglion and anastomoses distally with the posttrematic branch. The detailed course and branching patterns of these branches are described.