172 research outputs found
Compliance with child support orders in divorce cases
This paper examines compliance with child support orders by divorced fathers in Wisconsin. Compliance increases as the income of the father increases, although it falls in the highest income category. The "burden" of awards does not affect compliance unless more than 30 percent of income is owed. More stringent enforcement systems increase compliance. We find that most divorced fathers who are not complying with their orders do not have very low incomes, in contrast to noncomplying fathers in nonmarital cases. This suggests that the best policies to increase compliance among divorced fathers may differ from those for nonmarital fathers.
Patterns of Child Support Compliance in Wisconsin
This paper examines five-year compliance patterns among Wisconsin child support cases that came to court in 1986β88. We find only limited support for the common assumption that compliance with child support orders declines over time: the average percent paid is about .65 during each of the first five years. The most predominant trend is an increasing polarization into groups of nonpayers and full payers. Although we find considerable stability from year to year among nonpayers and full payers, there is considerable change over the course of five years. Compliance during the first year provides some indication of long-term compliance, but about half of fathers change their compliance rate over the period. We find important differences between divorced and nonmarital fathers, differences that are more pronounced than are apparent from a single year of data. Policy implications are discussed and further research is suggested.
Coordinated optimization of visual cortical maps (II) Numerical studies
It is an attractive hypothesis that the spatial structure of visual cortical
architecture can be explained by the coordinated optimization of multiple
visual cortical maps representing orientation preference (OP), ocular dominance
(OD), spatial frequency, or direction preference. In part (I) of this study we
defined a class of analytically tractable coordinated optimization models and
solved representative examples in which a spatially complex organization of the
orientation preference map is induced by inter-map interactions. We found that
attractor solutions near symmetry breaking threshold predict a highly ordered
map layout and require a substantial OD bias for OP pinwheel stabilization.
Here we examine in numerical simulations whether such models exhibit
biologically more realistic spatially irregular solutions at a finite distance
from threshold and when transients towards attractor states are considered. We
also examine whether model behavior qualitatively changes when the spatial
periodicities of the two maps are detuned and when considering more than 2
feature dimensions. Our numerical results support the view that neither minimal
energy states nor intermediate transient states of our coordinated optimization
models successfully explain the spatially irregular architecture of the visual
cortex. We discuss several alternative scenarios and additional factors that
may improve the agreement between model solutions and biological observations.Comment: 55 pages, 11 figures. arXiv admin note: substantial text overlap with
arXiv:1102.335
Child support reform: some analysis of the 1999 white paper
This paper uses a sample of lone mothers (and former lone mothers who are now repartnered) drawn from the 1997 Family Resources Survey to analyse the potential effects of reforming the UK system of Child Support. The main deficiency of the data is that non-resident fathers cannot be matched to the mothers in the data and this is overcome by exploiting information from another dataset which gives the joint distribution of the characteristics of separated parents. The effects of reforming the Child Support system is simulated for the amount of maintenance liabilities, the amount paid and the net incomes of households containing mothers with care and households containing non-resident fathers. The likely effects of the reform are simulated at various levels of compliance. The analysis highlights the need for further research into the incentive effects of Child Support on individual behaviour
Knowing with Which Eye We See: Utrocular Discrimination and Eye-Specific Signals in Human Visual Cortex
Neurophysiological and behavioral reports converge to suggest that monocular neurons in the primary visual cortex are biased toward low spatial frequencies, while binocular neurons favor high spatial frequencies. Here we tested this hypothesis with functional magnetic resonance imaging (fMRI). Human participants viewed flickering gratings at one of two spatial frequencies presented to either the left or the right eye, and judged which of the two eyes was being stimulated (utrocular discrimination). Using multivoxel pattern analysis we found that local spatial patterns of signals in primary visual cortex (V1) allowed successful decoding of the eye-of-origin. Decoding was above chance for low but not high spatial frequencies, confirming the presence of a bias reported by animal studies in human visual cortex. Behaviorally, we found that reliable judgment of the eye-of-origin did not depend on spatial frequency. We further analyzed the mean response in visual cortex to our stimuli and revealed a weak difference between left and right eye stimulation. Our results are thus consistent with the interpretation that participants use overall levels of neural activity in visual cortex, perhaps arising due to local luminance differences, to judge the eye-of-origin. Taken together, we show that it is possible to decode eye-specific voxel pattern information in visual cortex but, at least in healthy participants with normal binocular vision, these patterns are unrelated to awareness of which eye is being stimulated
Identification of a new pebp2 alpha A2 isoform from zebrafish runx2 capable of inducing osteocalcin gene expression in vitro
Introduction: RUNX2 (also known as CBFA1/Osf2/AML3/PEBP2 alpha A) is a transcription factor essential for bone formation in mammals, as well as for osteoblast and chondrocyte differentiation, through regulation of expression of several bone- and cartilage-related genes. Since its discovery, Runx2 has been the subject of intense studies, mainly focused in unveiling regulatory targets of this transcription factor in high vertebrates. However, no single study has been published addressing the role of Runx2 in bone metabolism of low vertebrates. While analyzing the zebrafish (Danio rerio) runx2 gene, we identified the presence of two orthologs of RUNX2, which we named runx2a and runx2b and cloned a pebp2 alpha A-like transcript of the runx2b gene, which we named pebp2 alpha A2. Materials and Methods: Zebrafish runx2b gene and cDNA were isolated by RT-PCR and sequence data mining. The 3D structure of runx2b runt domain was modeled using mouse Runx1 runt as template. The regulatory effect of pebp2 alpha A2 on osteocalcin expression was analyzed by transient co-transfection experiments using a luciferase reporter gene. Phylogenetic analysis of available Runx sequences was performed with TREE-PUZZLE 5.2. and MrBayes. Results and Conclusions: We showed that the runx2b gene structure is highly conserved between mammals and fish. Zebrafish runx2b has two promoter regions separated by a large intron. Sequence analysis suggested that the runx2b gene encodes three distinct isoforms, by a combination of alternative splicing and differential promoter activation, as described for the human gene. We have cloned a pebp2 alpha A-like transcript of the runx2b gene, which we named pebp2 alpha A2, and showed its high degree of sequence similarity with the mammalian pebp2 alpha A. The cloned zebrafish osteocalcin promoter was found to contain three putative runx2-binding elements, and one of them, located at -221 from the ATG, was capable of mediating pebp2 alpha A2 transactivation. In addition, cross-species transactivation was also confirmed because the mouse Cbfa1 was able to induce the zebrafish osteocalcin promoter, whereas the zebrafish pebp2 alpha A2 activated the murine osteocalcin promoter. These results are consistent with the high degree of evolutionary conservation of these proteins. The 3D structure of the runx2b runt domain was modeled based on the runt domain of mouse Runx1. Results show a high degree of similarity in the 3D configuration of the DNA binding regions from both domains, with significant differences only observed in non-DNA binding regions or in DNA-binding regions known to accommodate considerable structure flexibility. Phylogenetic analysis was used to clarify the relationship between the isoforms of each of the two zebrafish Runx2 orthologs and other Runx proteins. Both zebrafish runx2 genes clustered with other Runx2 sequences. The duplication event seemed, however, to be so old that, whereas Runx2b clearly clusters with the other fish sequences, it is unclear whether Runx2a clusters with Runx2 from higher vertebrates or from other fish.info:eu-repo/semantics/publishedVersio
Long-term, hormone-responsive organoid cultures of human endometrium in a chemically defined medium
Epithelial stem cell culture: modeling human disease and applications for regenerative medicine
On the Origin of the Functional Architecture of the Cortex
The basic structure of receptive fields and functional maps in primary visual cortex is established without exposure to normal sensory experience and before the onset of the critical period. How the brain wires these circuits in the early stages of development remains unknown. Possible explanations include activity-dependent mechanisms driven by spontaneous activity in the retina and thalamus, and molecular guidance orchestrating thalamo-cortical connections on a fine spatial scale. Here I propose an alternative hypothesis: the blueprint for receptive fields, feature maps, and their inter-relationships may reside in the layout of the retinal ganglion cell mosaics along with a simple statistical connectivity scheme dictating the wiring between thalamus and cortex. The model is shown to account for a number of experimental findings, including the relationship between retinotopy, orientation maps, spatial frequency maps and cytochrome oxidase patches. The theory's simplicity, explanatory and predictive power makes it a serious candidate for the origin of the functional architecture of primary visual cortex
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