The Pitfalls of Using a Child Support Schedule Based on Outdated Data

A strong rationale for updating child support guidelines arises from changes over time in the measurement of expenditures on children, as well as changes in the empirical relationship between expenditures on children and the income of parents. Such changes affect the accuracy of the numerics upon which states' child support guidelines are based. This study evaluates an alternative child support guideline that was proposed for Virginia and draws lessons for other states that similarly base their guidelines on older survey data. Regression results show that over time, the child expenditure and household income relationship has changed considerably. Furthermore, the largest increases in expenditures attributable to children have occurred for lower- and middle-income households

Sediment management and the renewability of floodplain clay for structural ceramics

The Netherlands has vast resources of clay that are exploited for the fabrication of structural ceramic products such as bricks and roof tiles. Most clay is extracted from the so-called embanked floodplains along the rivers Rhine and Meuse, areas that are flooded during high-discharge conditions. Riverside clay extraction is-at least in theory-compensated by deposition. Based on a sediment balance (deposition versus extraction), we explore the extent to which clay can be regarded as a renewable resource, with potential for sustainable use. Beyond that, we discuss the implications for river and sediment management, especially for the large engineering works that are to be undertaken to increase the discharge capacities of the Rhine and Meuse. Extraction rates are based on production statistics for clay, as well as those for fired end-products. Deposition rates are estimated from published and unpublished geological data (clay volumes and thicknesses, datings, etc.) and from morphological modeling studies. Comparisons between extraction and deposition are made at three different time-space scales: (1) long term (post-1850)/large scale (all Dutch floodplains), (2) present/large scale, and (3) present/site scale. The year 1850 is relevant because it approximately marks the beginning of the current, fully engineered river systems, in which depositional processes are constrained by dikes and groynes. As the Industrial Revolution began in the same period, post-1850 sediments can be identified by their pollution with heavy metals. (1) We estimate the post-1850 clay volume in situ at about 0.20 km(3), and the total extracted volume in the same period at about 0.17 km(3). This puts the net long-term average deposition rate of clay at similar to 1.3 million m(3)/year and the corresponding extraction rate at similar to 1.1 million m(3)/year. (2) Current accumulation is approximately 0.4 million m(3)/year and expected to increase, and current extraction is about 0.7 million m(3)/year and expected to decrease. (3) Clay extraction creates a depression that has an increased sediment-trapping efficiency. This local effect is not considered explicitly in large-scale morphological modeling. Based on maximum observed sedimentation rates, we estimate that replenishment of a clay site takes in the order of 150 years. As clay extraction lowers some 0.5 km(2) of floodplain yearly, a surface area of approximately 75 km(2) would be required for sustainable clay extraction. This is about 1/6 of the total surface area of the embanked floodplains. On the long term, clay extraction from the embanked floodplain depositional environment has been sustainable. At strongly decreasing deposition rates, the ratio between extraction and replenishment seems to have shifted towards unsustainable. However, current sedimentation is estimated conservatively. The site-scale approach suggests that, even if extraction would currently exceed deposition, this could be resolved with sediment management, that is, with site restoration measures aimed at higher sediment-trapping efficiency. Our results have implications for river engineering, especially where substantial digging is involved (floodplain lowering, high-discharge bypass channels, obstacle removal). First, this inevitably affects the clay resources that we studied, while resource sterilization should be avoided. Secondly, the effect that any form of digging has on subsequent sedimentation-increased rates-relates to long-term river maintenance. We conclude that floodplain clay is a renewable resource, especially if managed accordingly. Beyond that, we established that clay extraction is a significant, lasting factor in floodplain evolution along the Rhine and Meuse Rivers. The interests of the extractive industry and river managers could be served jointly with sediment management plans that are based on sediment-budget analyse

Genetic and environmental influences on MRI scan quantity and quality.

The current study provides an overview of quantity and quality of MRI data in a large developmental twin sample (N = 512, aged 7–9), and investigated to what extent scan quantity and quality were influenced by genetic and environmental factors. This was examined in a fixed scan protocol consisting of two functional MRI tasks, high resolution structural anatomy (3DT1) and connectivity (DTI) scans, and a resting state scan. Overall, scan quantity was high (88% of participants completed all runs), while scan quality decreased with increasing session length. Scanner related distress was negatively associated with scan quantity (i.e., completed runs), but not with scan quality (i.e., included runs). In line with previous studies, behavioral genetic analyses showed that genetics explained part of the variation in head motion, with heritability estimates of 29% for framewise displacement and 65% for absolute displacement. Additionally, our results revealed that subtle head motion (after exclusion of excessive head motion) showed lower heritability estimates (0–14%), indicating that findings of motion-corrected and quality-controlled MRI data may be less confounded by genetic factors. These findings provide insights in factors contributing to scan quality in children, an issue that is highly relevant for the field of developmental neuroscience

Protective wrapping of off-the-shelf components

System designers using off-the-shelf components (OTSCs), whose internals they cannot change, often use add-on “wrappers” to adapt the OTSCs’ behaviour as required. In most cases, wrappers are used to change “functional” properties of the components they wrap. In this paper we discuss instead protective wrapping, the use of wrappers to improve the dependability – i.e., “non-functional” properties like availability, reliability, security, and/or safety – of a component and thus of a system. Wrappers can improve dependability by adding fault tolerance, e.g. graceful degradation, or error recovery mechanisms. We discuss the rational specification of such protective wrappers in view of system dependability requirements, and highlight some of the design trade-offs and uncertainties that affect system design with OTSCs and wrappers, and that differentiate it from other forms of fault-tolerant design

The social brain in middle childhood: a neurobiological perspective on individual differences in social competence

The social relationships we form with other individuals are a fundamental part of human development. In order to establish these relationships it is of key importance for children to develop social competence (e.g. the ability to fulfill both others’ and own needs in a social context). The main goal of this thesis was to understand individual differences in social competence in middle childhood, by employing a combination of behavioral, neuroimaging and behavioral genetic approaches. Findings demonstrated that adults and children display social competence by showing helping behavior as a response to observed social exclusion. Additionally, in both adults and children social competence was associated with an integrated set of brain regions involved in socio-cognitive and affective processing, indicating that the neural architecture underlying social competence is already well established in middle childhood. Results on heritability of social competence indicate that individual differences in prosocial tendencies and brain structure might be partly influenced by genetic factors, but that neural and behavioral responses in a specific social context are largely shaped by an individual’s experiences in the (social) environment. This thesis highlights middle childhood as a possible window of opportunity for increasing social competence through training or intervention. Pathways through Adolescenc

Vroom in de Vinex : Kerk en civil society in de Leidsche Rijn

Vroom in de Vinex Marten van der Meulen deed onderzoek naar de rol van twee kerkopbouw projecten in de civil society van de Vinex-wijk Leidsche Rijn. Door middel van participerende observatie en andere kwalitatieve methoden onderzocht hij hoe de civil society zich in Leidsche Rijn ontwikkelt en hoe de kerkelijke opbouwprojecten hierin functioneren. Het blijkt dat een lokale civil society zich moeizaam ontwikkelt, en dat de kerkelijke projecten zich in een sociaal vacum bevinden: zij zijn amper verbonden met de professionele sociale infrastructuur die in Leidsche Rijn aan het ontstaan is. Toch hebben de kerken hun eigen visie op wat zij kunnen betekenen. Een van de projecten gebruikt het kapitaal dat besloten ligt in de oude, al bestaande sociale infrastructuur van twee dorpen die in de nieuwbouwwijk liggen. Met dit kapitaal initieert het project een Cultuurcampus, een samenwerking tussen verschillende maatschappelijke instellingen zoals een school, een bibliotheek en het maatschappelijk werk. Het gebruik van dit sociale kapitaal heeft echter niet alleen positieve consequenties: het belemmert ook de reikwijdte van de maatschappelijke participatie. Verder zien de kerkelijke opbouwprojecten mogelijkheden om met een spirituele bijdrage relevant te zijn voor de nieuwbouwbewoner. Deze religieuze visie op civil society stelt vragen bij de visie op maatschappelijke participatie die in de politiek, overheid en maatschappelijk middenveld dominant is, namelijk dat alleen sociaal-culturele functies van religieuze organisaties als maatschappelijke bijdrage gezien mogen worden. Met behulp van de filosoof Charles Taylor stelt Marten van der Meulen een model voor waarin religieuze bijdragen voluit gerekend worden als bijdragen aan de civil society.Stoffels, H.C. [Promotor

The Effectiveness of Software Diversity

This research exploits a collection of more than 2,500,000 programs, written to over 1,500 specifications (problems), the Online Judge programming competition. This website invites people all over the world to submit programs to these specifications, and automatically checks them against a benchmark. The submitter receives feedback, the most frequent responses being "Correct" and "Wrong Answer". This enormous collection of programs gives the opportunity to test common assumptions in software reliability engineering about software diversity, with a high confidence level and across several problem domains. The previous research has used collections of up to several dozens of programs for only one problem, which is large enough for exploratory insights, but not for statistical relevance. For this research, a test harness was developed which automatically extracts, compiles, runs and checks the programs with a benchmark. For most problems, this benchmark consists of 2,500 or 10,000 demands. The demands are random, or cover the entirety or a contiguous section of the demand space. For every program the test harness calculates: (1) The output for every demand in the benchmark. (2) The failure set, i.e. the demands for which the program fails. (3) The internal software metrics: Lines of Code, Halstead Volume, and McCabe's Cyclomatic Complexity. (4) The dependability metrics: number of faults and probability of failure on demand. The only manual intervention in the above is the selection of a correct program. The test harness calculates the following for every problem: (1) Various characteristics: the number of programs submitted to the problem, the number of authors submitting, the number of correct programs in the first attempt, the average number of attempts until a correct solution is reached, etc. (2) The grouping of programs in equivalence classes, i.e. groups' of programs with the same failure set. (3) The difficulty function for the problem, i.e. the average probability of failure of the program for different demands. (4) The gain of multipleversion software diversity in a 1-out-of-2 pair as a function of the pfd of the set of programs. (5) The additional gain of language diversity in the pair. (6) Correlations between internal metrics, and between internal metrics and dependability metrics. This research confirms many of the insights gained from earlier studies: (1) Software diversity is an effective means to increase the probability of failure on demand of a 1-out-of- 2 system. It decreases the probability of undetected failure on demand by on average around two orders of magnitude for reliable programs. (2) For unreliable programs the failure behaviour appears to be close to statistically independent. (3) Run-time checks reduce the probability of failure. However, the gain of run-time checks is much lower and far less consistent than that of multiple-version software diversity, i.e. it is fairly random whether a run-time check matches the faults actually made in programs. (4) Language diversity in a diverse pair provides an additional gain in the probability of undetected failure on demand, but this gain is not very high when choosing from the programming languages C, C++ and Pascal. (5) There is a very strong correlation between the internal software metrics. The programs in the Online Judge do not behave according to some common assumptions: (1) For a given specification, there is no correlation between selected internal software metrics (Lines of Code, Halstead Volume and McCabe's Cyclomatic Complexity) and dependability metrics (pfd and Number of Faults) of the programs implementing it. This result could imply that for improving dependability, it is not effective to require programmers to write programs within given bounds for these internal software metrics. (2) Run-time checks are still effective for reliable programs. Often, programmers remove runtIme checks at the end of the development process, probably because the program is then deemed to be correct. However, the benefit of run-time checks does not correlate with pfd, i.e. they. are as effective for reliable as for unreliable programs. They are also shown to have a negliigible adverse impact on the program's dependability

Primary Central Nervous System Lymphoma: Diagnostic evaluation, neurocognitive functioning and health-related quality of life

This thesis describes the epidemiology (incidence and prognosis), the diagnostic evaluation and neurocognitive functioning and health-related quality of life in primary central nervous system lymphoma patient

Screening for Down's syndrome: effects, safety, and cost effectiveness of first and second trimester strategies commentary: rasults may not be widely applicable authors' response

Objective: To compare the effects, safety, and cost effectiveness of antenatal screening strategies for Down's syndrome. Design: Analysis of incremental cost effectiveness. Setting: United Kingdom. Main outcome measures: Number of liveborn babies with Down's syndrome, miscarriages due to chorionic villus sampling or amniocentesis, healthcare costs of screening programme, and additional costs and additional miscarriages per additional affected live birth prevented by adopting a more effective strategy. Results: Compared with no screening, the additional cost per additional liveborn baby with Down's syndrome prevented was £22 000 for measurement of nuchal translucency. The cost of the integrated test was £51 000 compared with measurement of nuchal translucency. All other strategies were more costly and less effective, or cost more per additional affected baby prevented. Depending on the cost of the screening test, the first trimester combined test and the quadruple test would also be cost effective options. Conclusions: The choice of screening strategy should be between the integrated test, first trimester combined test, quadruple test, or nuchal translucency measurement depending on how much service providers are willing to pay, the total budget available, and values on safety. Screening based on maternal age, the second trimester double test, and the first trimester serum test was less effective, less safe, and more costly than these four options