Siblings and Educational Attainment in West Germany

Individual decisions on education are still an important topic in social sciences research. Our goal is an analysis of the impact of siblings on educational attainment in West Germany. Theories of educational decisions in a family context suggest several possible effects of siblings. During the 1990s, several authors analyzed this relationship for the United States and came up with contradictory results on the relative importance of different factors. Consequently, an empirical analysis is required, which is provided in this paper based on data from the GSOEP. In order to control for unobservable heterogeneity in educational decisions, several empirical specifications including propensity score matching are tested. The results suggest that boys are favored by their parents relative to girls. Furthermore, the gender of their siblings shows no significant impact on the educational attainment of boys, while a significant effect is found for girls. Finally, the educational attainment of an elder sibling shows a significant and positive effect on education decisions of the second child. --Unobservable heterogeneity,matching,ordered-probit

Reelin Signaling in the Migration of Ventral Brain Stem and Spinal Cord Neurons

The extracellular matrix protein Reelin is an important orchestrator of neuronal migration during the development of the central nervous system. While its role and mechanism of action have been extensively studied and reviewed in the formation of dorsal laminar brain structures like the cerebral cortex, hippocampus, and cerebellum, its functions during the neuronal migration events that result in the nuclear organization of the ventral central nervous system are less well understood. In an attempt to delineate an underlying pattern of Reelin action in the formation of neuronal cell clusters, this review highlights the role of Reelin signaling in the migration of neuronal populations that originate in the ventral brain stem and the spinal cord

Siblings and Educational Attainment in West Germany

Individual decisions on education are still an important topic in social sciences research. Our goal is an analysis of the impact of siblings on educational attainment in West Germany. Theories of educational decisions in a family context suggest several possible effects of siblings. During the 1990s, several authors analyzed this relationship for the United States and came up with contradictory results on the relative importance of different factors. Consequently, an empirical analysis is required, which is provided in this paper based on data from the GSOEP. In order to control for unobservable heterogeneity in educational decisions, several empirical specifications including propensity score matching are tested. The results suggest that boys are favored by their parents relative to girls. Furthermore, the gender of their siblings shows no significant impact on the educational attainment of boys, while a significant effect is found for girls. Finally, the educational attainment of an elder sibling shows a significant and positive effect on education decisions of the second child

Studying subcellular detail in fixed astrocytes: dissociation of morphologically intact glial cells (DIMIGs)

Studying the distribution of astrocytic antigens is particularly hard when they are localized in their fine, peripheral astrocyte processes (PAPs), since these processes often have a diameter comparable to vesicles and small organelles. The most appropriate technique is immunoelectron microscopy, which is, however, a time-consuming procedure. Even in high resolution light microscopy, antigen localization is difficult to detect due to the small dimensions of these processes, and overlay from antigen in surrounding non-glial cells. Yet, PAPs frequently display antigens related to motility and glia-synaptic interaction. Here, we describe the dissociation of morphologically intact glial cells (DIMIGs), permitting unambiguous antigen localization using epifluorescence microscopy. Astrocytes are dissociated from juvenile (p13–15) mouse cortex by applying papain treatment and cytospin centrifugation to attach the cells to a slide. The cells and their complete processes including the PAPs is thus projected in 2D. The entire procedure takes 2.5–3 h. We show by morphometry that the diameter of DIMIGs, including the PAPs is similar to that of astrocytes in situ. In contrast to cell culture, results derived from this procedure allow for direct conclusions relating to (1) the presence of an antigen in cortical astrocytes, (2) subcellular antigen distribution, in particular when localized in the PAPs. The detailed resolution is shown in an exemplary study of the organization of the astrocytic cytoskeleton components actin, ezrin, tubulin, and GFAP. The distribution of connexin 43 in relation to a single astrocyte's process tree is also investigated

The impact of a church-based physical activity intervention on exercise adherence in middle-aged women.

Women are at risk of cardiovascular disease which regular physical activity has been shown to reduce; yet 60% do not exercise 30 minutes daily for minimal health benefits. This study determined the effectiveness of a 24-week church-based physical activity intervention for middle-aged women (n = 12) aged 35 to 65 years in increasing and maintaining weekly moderate-intensity activity. An intervention group and control group logged weekly exercise activity. They received separate intervention including encouragement to exercise with a partner and attend a biweekly support meeting for Bible study and wellness education during phase one and two, respectively. The entire sample did increase exercise time during the study (p = .000). The results offer wellness programs aid in exercise adherence development

Extracting a less model dependent cosmic ray composition from Xmax distributions

Knowledge of the acceleration mechanisms, possible sources and arrival direction distribution of ultra high energy cosmic rays can be furthered by increasing our understanding of the cosmic ray mass composition. The Pierre Auger Observatory measures the depth of shower maximum (Xmax [max subscript]) of ultra high energy cosmic rays, an observable which is sensitive to the mass of the cosmic ray, and often analysed in mass composition studies. At ultra high energies, the results of mass composition studies depend strongly on the particle interaction predictions of the assumed hadronic interaction model. A novel approach to reduce the model dependency in the interpretation of the mass composition will be outlined in this thesis. The Xmax [max subscript] predictions of the models were parameterised in terms of the primary mass. The mass composition fractions and some of the parameterisation coefficients are then fitted to the data, resulting in a mass composition estimate which is of reduced model dependency. The results of this approach applied to Pierre Auger Observatory data are presented.Thesis (Ph.D.) -- University of Adelaide, School of Physical Sciences, 201

Patterning and gastrulation defects caused by the tw18 lethal are due to loss of Ppp2r1a

The mouse t haplotype, a variant 20 cM genomic region on Chromosome 17, harbors 16 embryonic control genes identified by recessive lethal mutations isolated from wild mouse populations. Due to technical constraints so far only one of these, the tw5 lethal, has been cloned and molecularly characterized. Here we report the molecular isolation of the tw18 lethal. Embryos carrying the tw18 lethal die from major gastrulation defects commencing with primitive streak formation at E6.5. We have used transcriptome and marker gene analyses to describe the molecular etiology of the tw18 phenotype. We show that both WNT and Nodal signal transduction are impaired in the mutant epiblast, causing embryonic patterning defects and failure of primitive streak and mesoderm formation. By using a candidate gene approach, gene knockout by homologous recombination and genetic rescue, we have identified the gene causing the tw18 phenotype as Ppp2r1a, encoding the PP2A scaffolding subunit PR65alpha. Our work highlights the importance of phosphatase 2A in embryonic patterning, primitive streak formation, gastrulation, and mesoderm formation downstream of WNT and Nodal signaling

Reelin and CXCL12 regulate distinct migratory behaviors during the development of the dopaminergic system

The proper functioning of the dopaminergic system requires the coordinated formation of projections extending from dopaminergic neurons in the substantia nigra (SN), ventral tegmental area (VTA) and retrorubral field to a wide array of forebrain targets including the striatum, nucleus accumbens and prefrontal cortex. The mechanisms controlling the assembly of these distinct dopaminergic cell clusters are not well understood. Here, we have investigated in detail the migratory behavior of dopaminergic neurons giving rise to either the SN or the medial VTA using genetic inducible fate mapping, ultramicroscopy, time-lapse imaging, slice culture and analysis of mouse mutants. We demonstrate that neurons destined for the SN migrate first radially and then tangentially, whereas neurons destined for the medial VTA undergo primarily radial migration. We show that tangentially migrating dopaminergic neurons express the components of the reelin signaling pathway, whereas dopaminergic neurons in their initial, radial migration phase express CXC chemokine receptor 4 (CXCR4), the receptor for the chemokine CXC motif ligand 12 (CXCL12). Perturbation of reelin signaling interferes with the speed and orientation of tangentially, but not radially, migrating dopaminergic neurons and results in severe defects in the formation of the SN. By contrast, CXCR4/CXCL12 signaling modulates the initial migration of dopaminergic neurons. With this study, we provide the first molecular and functional characterization of the distinct migratory pathways taken by dopaminergic neurons destined for SN and VTA, and uncover mechanisms that regulate different migratory behaviors of dopaminergic neurons

A Portfolio Decision Analysis Study for Improving Consequence of Facility Failure Indices

The United States Air Force partially integrated the Mission Dependency Index (MDI) into its portfolio project selection model by assigning an MDI value to a facility type or real property category code (CATCODE) in lieu of assigning a unique MDI value to each facility through a structured interview process. This took an initial step to improve the Air Forces asset management practices; however, it failed to accurately capture the consequence of facility failure in some cases. Although a process to adjudicate the MDI value of individual facilities was created, it is still unknown how much the surveyed MDI value deviates from the CATCODE assigned MDI value and how this influences the Air Forces annual project portfolio selection model. The purpose of this research effort is to measure the deviation in MDI values produced from surveys and the adjudication process with the CATCODE assigned MDI values. It also uses a deterministic approach to portfolio decision analysis to determine the influence these surveyed and adjudicated MDI values have on the Air Forces project portfolio selection model. This research effort serves to provide insight to the Air Force Installation Mission Support Center and the Air Force Civil Engineer Center of the value and utility of surveyed and adjudicated MDI information when compared to their CATCODE assigned counterparts