Essays in Empirical Labor Economics: Evidence on Health, Education and Migration

This dissertation empirically investigates forces that shape the human capital base in the German labor market. Its three essays provide evidence on governmental interventions that promote or change the supply of human capital and impact health, education and migration, respectively

Mass concentration in a nonlocal model of clonal selection

Self-renewal is a constitutive property of stem cells. Testing the cancer stem cell hypothesis requires investigation of the impact of self-renewal on cancer expansion. To understand better this impact, we propose a mathematical model describing dynamics of a continuum of cell clones structured by the self-renewal potential. The model is an extension of the finite multi-compartment models of interactions between normal and cancer cells in acute leukemias. It takes a form of a system of integro-differential equations with a nonlinear and nonlocal coupling, which describes regulatory feedback loops in cell proliferation and differentiation process. We show that such coupling leads to mass concentration in points corresponding to maximum of the self-renewal potential and the model solutions tend asymptotically to a linear combination of Dirac measures. Furthermore, using a Lyapunov function constructed for a finite dimensional counterpart of the model, we prove that the total mass of the solution converges to a globally stable equilibrium. Additionally, we show stability of the model in space of positive Radon measures equipped with flat metric. The analytical results are illustrated by numerical simulations

From Elections to Democracy: Building Accountable Government in Hungary and Poland by Susan Rose‐Ackerman

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97210/1/j.1538-165X.2006.tb01462.x.pd

The Effects of Free Childcare on Labor Supply and Children

Many governments have introduced generous childcare subsidies to allow all children access to early childhood education. The effects of these costly programs are however still debated. In this paper, we use the introduction of free public childcare in several states in Germany to analyze its effects on children and their families. Our results suggest that the effects of public childcare depend on the child's age: free public childcare for 3-year-olds increases attendance and female labor supply, while it reduces childcare attendance for 5-and 6-year-olds. After the policy reforms, 3-year-olds improve their developmental skills in the short-run while there might be some detrimental effects for older preschool children

The pollination of Epipactis Zinn, 1757 (Orchidaceae) species in Central Europe – the significance of chemical attractants, floral morphology and concomitant insects

A series of studies on pollination biology of the Epipactis atrorubens (Hoffm.) Besser, E. purpurata Sm., and E. palustris (L.) Crantz populations was conducted in Poland, Lithuania and Czech Republic between 2003 and 2010. The research focused on pollinators and visitors to aforementioned orchid species as well as on the chemical analysis of orchids' nectar which was done using the GC/MS method. It was found that: 1) the type of pollinators depends on the orchid population size and the surrounding environment, where the temperature and amount of precipitation during the vegetative season are the most vital factors; 2) pollinators and visitors to the examined orchids might differ in successive growing seasons; 3) the studied Epipactis species differ in the chemical composition of their nectar and its scent, which can influence their pollination biology; 4) the tendency to autogamy observed in E. purpurata might be due to lack of pollinators in its habitats

The pollination of Epipactis Zinn, 1757 (Orchidaceae) species in Central Europe – the significance of chemical attractants, floral morphology and concomitant insects

A series of studies on pollination biology of the Epipactis atrorubens (Hoffm.) Besser, E. purpurata Sm., and E. palustris (L.) Crantz populations was conducted in Poland, Lithuania and Czech Republic between 2003 and 2010. The research focused on pollinators and visitors to aforementioned orchid species as well as on the chemical analysis of orchids' nectar which was done using the GC/MS method. It was found that: 1) the type of pollinators depends on the orchid population size and the surrounding environment, where the temperature and amount of precipitation during the vegetative season are the most vital factors; 2) pollinators and visitors to the examined orchids might differ in successive growing seasons; 3) the studied Epipactis species differ in the chemical composition of their nectar and its scent, which can influence their pollination biology; 4) the tendency to autogamy observed in E. purpurata might be due to lack of pollinators in its habitats

The Iowa Homemaker vol.1, no.12

Table of Contents Home Economics Celebrates Third Annual “Hec Day” by Marjorie Miller, page 1 To Live to Be a Hundred Is Your Privilege by Florence M. Busse, page 2 Mere Lines – They Make or Mar Our Costumes by Anna Prang, page 3 How False Ideas Mar Beauty by Mae Kelly, page 4 What Kind of Breakfasts Do You Serve? by N. Beth Bailey, page