Economic Precariousness and the Transition to Parenthood:A Dynamic and Multidimensional Approach

Economic precariousness has taken on a central role in explanations of the postponement of childbearing in developed societies. However, most studies conceptualize and operationalize precariousness as being static and one-dimensional, which provides only a partial perspective on the links between precariousness and fertility. In this paper, we study precariousness as a dynamic and multidimensional concept, distinguishing between past and current precariousness as well as between precariousness relating to income and to employment. Analyses are based on Dutch full-population register data. We select all inhabitants of the Netherlands who left education in 2006 and follow them until 2018. Event history analyses show that current and past income and employment precariousness all have independent negative effects on the first birth rate for men. Current and past employment precariousness and past income precariousness also reduce the first birth rate for women, but current income precariousness increases women’s probability of first conception. When precariousness is both persistent and multidimensional, it is associated with a threefold decrease in the monthly probability of conceiving a first child for men and almost a halving of the probability for women. Our analyses show the need for going beyond static and one-dimensional analyses in order to understand how economic precariousness may affect fertility behaviour

Temporary Employment and Family Formation:An Income or Insecurity Effect?

Recent studies show that temporary workers postpone family formation transitions, but it remains unclear whether this effect is due to the lower income or the stronger perceptions of job insecurity that go with a temporary contract. To address this question, we link data from a large-scale survey among Dutch employees to longitudinal population register data on marriage and first births. Logistic regression models estimate the effects of temporary employment on marriage and first birth, and mediation analyses assess to what extent these effects are explained by income and perceptions of job insecurity. Results show that temporarily employed women delay first birth. There is also some evidence that temporarily employed men postpone marriage and first birth. These effects are partly explained by income, which increases marriage and first birth rates among men and women alike. Perceptions of job insecurity generally had little effect on family formation, although higher marriage rates were found among women who experienced affective job insecurity. Overall, this shows that it is their low income rather than their feelings of insecurity about future employment that explains why temporary employees postpone family formation

Energy coupling of membrane transport and efficiency of sucrose dissimilation in yeast

Proton coupled transport of α-glucosides via Mal11 into Saccharomyces cerevisiae costs one ATP per imported molecule. Targeted mutation of all three acidic residues in the active site resulted in sugar uniport, but expression of these mutant transporters in yeast did not enable growth on sucrose. We then isolated six unique transporter variants of these mutants by directed evolution of yeast for growth on sucrose. In three variants, new acidic residues emerged near the active site that restored proton-coupled sucrose transport, whereas the other evolved transporters still catalysed sucrose uniport. The localization of mutations and transport properties of the mutants enabled us to propose a mechanistic model of proton-coupled sugar transport by Mal11. Cultivation of yeast strains expressing one of the sucrose uniporters in anaerobic, sucrose-limited chemostat cultures indicated an increase in the efficiency of sucrose dissimilation by 21% when additional changes in strain physiology were taken into account. We thus show that a combination of directed and evolutionary engineering results in more energy efficient sucrose transport, as a starting point to engineer yeast strains with increased yields for industrially relevant products

Effect of prevention measures on incidence of human listeriosis, France, 1987-1997.

To assess the impact of preventive measures by the food industry, we analyzed food monitoring data as well as trends in the incidence of listeriosis estimated through three independent sources: the National Reference Center of Listeriosis; a laboratory-based active surveillance network; and two consecutive nationwide surveys of public hospital laboratories. From 1987 to 1997, the incidence of listeriosis decreased by an estimated 68%. A substantial reduction in the proportion of Listeria monocytogenes-contaminated products was observed at the retail level. The temporal relationship between prevention measures by the food industry, reduction in L. monocytogenes-contaminated foodstuffs, and reduction in listeriosis incidence suggests a causal relationship and indicates that a substantial part of the reduction in illness is related to prevention efforts

Both raloxifene and estrogen reduce major cardiovascular risk factors in healthy postmenopausal women; A 2 year, placebo-controlled study

Currently raloxifene, a selective estrogen receptor modulator, is being investigated as a potential alternative for postmenopausal hormone replacement to prevent osteoporosis and cardiovascular disease. We compared the 2-year effects of raloxifene on a wide range of cardiovascular risk factors with those of placebo and conjugated equine estrogens (CEEs). Analyses were based on 56 hysterectomized but otherwise-healthy postmenopausal women aged 54.8±3.5 (mean±SD) years who entered this double- blind study and who were randomly assigned to raloxifene hydrochloride 60 mg/d (n = 15) or 150 mg/d (n= 13), placebo (n= 13), or CEEs 0.625 mg/d (n = 15). At baseline and after 6, 12, and 24 months of treatment, we assessed serum lipids, blood pressure, glucose metabolism, C-reactive protein, and various hemostatic parameters. Compared with placebo, both raloxifene and CEEs lowered the level of low density lipoprotein cholesterol by 0.53 to 0.79 mmol/L (all P<0.04) and lowered, at 24 months, the level of fibrinogen by 0.71 to 0.86 g/L (all P<0.05). The effects of raloxifene and CEEs did not differ significantly. In contrast to raloxifene, from 6 months on CEEs increased high density lipoprotein cholesterol by 0.25 to 0.29 mmol/L and reduced plasminogen activator inhibitor-1 antigen by 30.6 to 48.6 ng/mL (all P<0.02 versus both placebo and raloxifene). CEEs transiently increased C- reactive protein by 1.0 mg/L at 6 months (P<0.05 versus placebo) and- prothrombin-derived fragment F1 +2 by 0.79 nmol/L at 12 months (P<0.001 versus placebo). Finally, from 12 months on, CEEs increased triglycerides by 0.33 to 0.56 mmol/L (all P<0.05 versus both placebo and raloxifene). Our findings suggest that in healthy postmenopausal women, raloxifene and estrogen monotherapy have similar beneficial effects on low density lipoprotein cholesterol and fibrinogen levels. These treatments differ, however, in their effects on high density lipoprotein cholesterol, triglycerides, and plasminogen activator inhibitor-1 and possibly in their effects on prothrombin fragment F1+2 and C-reactive protein