Long-term trends in income and wealth inequality in the Netherlands: 1808-1940

Obwohl die wirtschaftliche Entwicklung der Niederlande einen anderen Weg verfolgte, als der von den Länder, die Kuznets in seiner Studie über langfristige Einkommensverteilung untersucht hatte, wiesen die Niederländer das gleiche umgekehrte U-Muster der Ungleichheit auf, das Kuznets entwickelt hatte. Von der Mitte des 19. Jahrhunderts bis ungefähr 1880 vergrößerte sich der Grad der Ungleichheit und verringerte sich allmählich danach. Während des Ersten Weltkrieges ergab sich eine dramatische Verbreitung der Einkommensunterschiede, die anschließend dann mehr als aufgehoben wurden. Das Muster der Einkommensverteilung direkt vor und direkt nach dem Ersten Weltkrieg war ähnlich. Zwar charakterisierten zyklische Entwicklungen die Geschichte der Einkommensverteilung in den Jahren zwischen den Kriegen, für den untersuchten Zeitraum insgesamt war jedoch die Entwicklung von Einkommens- und Reichtumsungleichheit deutlich im Rückgang begriffen. (KW)Although the economic development of the Netherlands took a different path from that of the countries investigated by Kuznets in his study of long-run income distribution patterns, the Netherlands shared in the inverse-U pattern of inequality established by him. From the mid-nineteenth century until about 1880 levels of inequality increased, declining gradually thereafter. During WWI there was a dramatic widening of income differentials, which were subsequently more than reversed. The immediate pre- and post-WWI pattern of wealth distribution was similar. While cyclical developments characterized the distribution history of the inter-war years, for the period as a whole the trend of both income and wealth inequality was firmly downwards

Improvement of Energy Efficiency for Wastewater Treatment

Wastewater treatment requires the elimination of pathogens and reduction of organic matter in the treated sludge to acceptable levels. One process used to achieve this is Autothermal Thermophylic Aerobic Digestion (ATAD), which relies on promoting non-pathogenic thermophilic bacteria to digest organic matter and kill pathogens through metabolic heat generation. This process requires continuous aeration that may be energy consuming, and the final aim of the study is to identify how the process design can minimize the energy input per mass of treated sludge. Appropriate modeling of the reactor process is an essential ingredient, so we explore properties of an existing model and propose a simplified alternative model

Executive and Daily Life Functioning Influence the Relationship Between ADHD and Mood Symptoms in University Students

Objectives: Many studies have indicated a close relationship between ADHD and mood symptoms in university students. In the present study, we explore the role of daily functional impairments and executive functioning in the ADHD–mood relationship. Method: A total of 343 adults (126 males) filled out (a) the Conners’ Adult ADHD Rating Scale, (b) the Depression Anxiety and Stress Scale, (c) the Weiss Functional Impairment Rating Scale, and (d) the Executive Function Index Scale. Results: The correlation between mood symptoms and ADHD was .48 (moderate correlation) and dropped to .15 (weak correlation) when controlling for functional problems and executive functioning. Hierarchical regression analyses showed that both functional impairments and executive functioning significantly explained 42% to 53% of the variance of mood symptoms. The addition of ADHD symptoms to the model slightly increased the explained mood variance by only 1%. Conclusion: These findings underline the role of experienced difficulties in triggering mood symptoms in ADHD symptomatology

Thin-film-integrated power inductor on Si and its performance in an 8-MHz buck converter

This paper presents a microinductor fabricated on silicon using electrochemical techniques that has high efficiency in a low power dc–dc converter. Small signal measurements show a flat frequency response up to 20 MHz with a self resonant frequency of 130 MHz. The inductance at low frequency is approximately 440 nH with a dc resistance of 0.5 Ω, and a high quality factor of 11.7 at 5.5 MHz. The current handling capability test shows less than 10% decrease in inductance at 500-mA current. The performance of the microinductor has been compared to a conventional chip inductor in a commercially available 8-MHz buck converter. The converter maximum efficiency when using the microinductor is shown to be approximately 3% lower than the one using the conventional discrete chip inductor. However, the profile of the microinductor is much lower than that of the discrete chip inductor. The maximum efficiency of the microinductor in the converter is estimated to be approximately 92%

Brain lateralization and self-reported symptoms of ADHD in a population sample of adults:A dimensional approach

Many clinical studies reported a compromised brain lateralization in patients with Attention-Deficit/Hyperactivity Disorder (ADHD) without being conclusive about whether the deficit existed in the left or right hemisphere. It is well-recognized that studying ADHD dimensionally is more controlled for comorbid problems and medication effects, and provides more accurate assessment of the symptoms. Therefore, the present study applied the dimensional approach to test the relationship between brain lateralization and self-reported ADHD symptoms in a population sample. Eighty-five right-handed university students filled in the Conners’ Adult ADHD Rating Scales and performed a lateralization reaction time task. The task consists of two matching conditions: one condition requires nominal identification for letters tapping left hemisphere specialization (Letter Name-Identity condition) and the other one requires physical and visuospatial identification for shapes tapping right hemisphere specialization (Shape Physical-Identity condition). The letters or shapes to be matched are presented in left or right visual field of a fixation cross. For both task conditions, brain lateralization was indexed as the difference in mean reaction time between left and right visual field. Linear regression analyses, controlled for mood symptoms reported by a depression, anxiety and stress scale, showed no relationship between the variables. These findings from a population sample of adults do not support the dimensionality of lateralized information processing deficit in ADHD symptomatology. However, group comparison analyses showed that subjects with high level of inattention symptoms close to or above the clinical cut-off had a reduced right hemisphere processing in the Shape Physical-Identity condition

Testing assumptions for endophenotype studies in ADHD: Reliability and validity of tasks in a general population sample

BACKGROUND: Advances in both genetic and cognitive-experimental studies on attention deficit hyperactivity disorder (ADHD) have opened new opportunities for cognitive endophenotype research. In such genetic designs the focus is on individual differences in characteristics, associated with ADHD, that can be measured reliably over time. Genetic studies that take a 'quantitative trait loci' approach hypothesise that multiple susceptibility genes contribute to a continuous dimension of ADHD symptoms. As an important initial step, we aimed to investigate the underlying assumptions that (1) key cognitive-experimental tasks indicate adequate test-retest reliability and (2) ADHD symptom scores in a general population sample are associated with performance on these tasks. METHODS: Forty-nine children were assessed on a go/no-go task and a reaction time task (the 'fast task') that included manipulations with event rate and incentives. The children were assessed twice, with a test-retest interval of two weeks. RESULTS: The majority of the task variables demonstrated moderate-to-good test-retest reliability. The correlations between teacher ratings of ADHD symptoms and key task variables were .4–.6: ADHD symptoms were associated with poor performance (especially high reaction time variability) in a slow baseline condition, whereas there was low or no association in conditions with a faster event rate or incentives. In contrast, no clear pattern of findings emerged based on parent ratings of ADHD symptoms. CONCLUSION: The data support the usefulness of the go/no-go and fast tasks for genetic studies, which require reliable and valid indices of individual differences. The overall pattern of associations between teacher ratings of ADHD symptoms and task variables is consistent with effects of event rate and incentives on performance, as predicted by the model of activation and arousal regulation. The lack of a clear pattern of findings with parent ratings of ADHD symptoms warrants further study

Error monitoring and daily life executive functioning

Error monitoring during task execution is reflected in post-error slowing (PES), which refers to the tendency to slow down performance after making an error in order to prevent future mistakes. The key question of the present study is whether poor error monitoring (reduced magnitude of PES) has negative consequences for daily life executive function skills, as well as functioning in different life settings such as work, family, social, and academic settings. Eighty-five university students performed a lexical decision task and completed The Executive Function Index Scale (EFI), and the Weiss Functional Impairments Rating Scale (WFIRS). Individual academic achievement was measured using the Grade Point Average. Statistical analysis revealed that a decreased magnitude of PES was weakly associated with less efficient planning (one of the executive functions). Results suggest that error monitoring, as measured by PES, was not associated with functioning in a naturalistic environment, but could be interpreted to some extent as an experimental marker of planning in daily life executive functioning

Linking state regulation, brain laterality, and self-reported attention-deficit/hyperactivity disorder (ADHD) symptoms in adults

Introduction: Many clinical studies have shown that performance of subjects with attention-deficit/hyperactivity disorder (ADHD) is impaired when stimuli are presented at a slow rate compared to a medium or fast rate. According to the cognitive–energetic model, this finding may reflect difficulty in allocating sufficient effort to regulate the motor activation state. Other studies have shown that the left hemisphere is relatively responsible for keeping humans motivated, allocating sufficient effort to complete their tasks. This leads to a prediction that poor effort allocation might be associated with an affected left-hemisphere functioning in ADHD. So far, this prediction has not been directly tested, which is the aim of the present study. Method: Seventy-seven adults with various scores on the Conners’ Adult ADHD Rating Scale performed a lateralized lexical decision task in three conditions with stimuli presented in a fast, a medium, and a slow rate. The left-hemisphere functioning was measured in terms of visual field advantage (better performance for the right than for the left visual field). Results: All subjects showed an increased right visual field advantage for word processing in the slow presentation rate of stimuli compared to the fast and the medium rate. Higher ADHD scores were related to a reduced right visual field advantage in the slow rate only. Conclusions: The present findings suggest that ADHD symptomatology is associated with less involvement of the left hemisphere when extra effort allocation is needed to optimize the low motor activation state

Genetic analysis of reaction time variability: room for improvement?

Background Increased reaction time variability (RTV) on cognitive tasks requiring a speeded response is characteristic of several psychiatric disorders. In attention deficit hyperactivity disorder (ADHD), the association with RTV is strong phenotypically and genetically, yet high RTV is not a stable impairment but shows ADHD-sensitive improvement under certain conditions, such as those with rewards. The state regulation theory proposed that the RTV difference score, which captures change from baseline to a rewarded or fast condition, specifically measures ‘state regulation'. By contrast, the interpretation of RTV baseline (slow, unrewarded) scores is debated. We aimed to investigate directly the degree of phenotypic and etiological overlap between RTV baseline and RTV difference scores. Method We conducted genetic model fitting analyses on go/no-go and fast task RTV data, across task conditions manipulating rewards and event rate, from a population-based twin sample (n=1314) and an ADHD and control sibling-pair sample (n=1265). Results Phenotypic and genetic/familial correlations were consistently high (0.72-0.98) between RTV baseline and difference scores, across tasks, manipulations and samples. By contrast, correlations were low between RTV in the manipulated condition and difference scores. A comparison across two different go/no-go task RTV difference scores (slow-fast/slow-incentive) showed high phenotypic and genetic/familial overlap (r=0.75-0.83). Conclusions Our finding that RTV difference scores measure largely the same etiological process as RTV under baseline condition supports theories emphasizing the malleability of the observed high RTV. Given the statistical shortcomings of difference scores, we recommend the use of RTV baseline scores for most analyses, including genetic analyse