Achieving a new dimension: Children integrate three stimulus dimensions in volume estimations.

Although J. Piaget (1968) assumed that children up to 7 years old are unable to consider more than 1 stimulus dimension in their judgments, subsequent research has demonstrated that preschoolers can consider 2 dimensions, such as the width and length of rectangles to estimate their area (F. Wilkening, 1979). The present study addressed the question of whether children can also take 3 stimulus dimensions into account. Kindergartners, 1st and 3rd graders, and adults (N = 73) estimated the volume of cuboids that required the consideration of 3 dimensions: width, height, and length. The results showed that the majority of kindergartners already based their volume estimations on all 3 dimensions. A considerable proportion of kindergartners even integrated width, height, and length multiplicatively. There was no dramatic improvement with age, implying the implicit understanding of volume to develop relatively early in childhood. The results are discussed in light of children’s cognitive competencies concerning multidimensional reasoning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential susceptibility to discipline: The moderating effect of child temperament on the association between maternal discipline and early childhood externalizing problems.

This study investigated the interaction of child temperament and maternal discipline in the prediction of externalizing problems in early childhood. Interaction effects were evaluated in a sample of 227 one- to three-year-old children with relatively high externalizing problems scores on the Child Behavior Checklist/1 1/2-5. Child temperament was reported by the mothers, maternal discipline was observed in a laboratory session, and child outcome measures included both mother-reported externalizing problems and observed physical aggression. Results indicate that children with difficult temperaments are more susceptible to negative discipline (i.e., they showed more externalizing problems) as well as more susceptible to positive discipline (i.e., they showed fewer externalizing problems and less physical aggression), as compared with children with relatively easy temperaments. These findings provide empirical evidence for the differential susceptibility hypothesis and suggest directions for enhancing the effectiveness of interventions aimed at reducing early childhood externalizing problems. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Patient and staff radiation dose in fluoroscopy-guided TIPS procedures and dose reduction, using dedicated fluoroscopy exposure settings

Fluoroscopy guided interventions, such as transjugular intrahepatic portosystemic shunt (TIPS) procedures, can results in relatively high radiation doses to patients and staff. The purpose of this study was to evaluate the possible benefit of dedicated fluoroscopy exposure factors in the reduction of doses. Doses to patients and staff were measured during fluoroscopy-guided TIPS procedures in two Dutch university hospitals. Patient doses were calculated from dose-area product (DAP) measurements, entrance beam dimensions and DAP conversion factors. Staff doses were measured outside lead aprons using electronic personal dosemeters. Average patient entrance skin dose (ESD) rate during fluoroscopy was 49 mGy min-1 (13 cases, average fluoroscopy duration 32 min) in one hospital, and 6 mGy min-1 (10 cases, average fluoroscopy duration 50 min) in the other. Estimated staff effective dose per procedure was 28 microSv average in the first hospital compared with 4 microSv average in the other. The use of dedicated fluoroscopy exposure factors, with a relatively high tube voltage and lower tube current resulted in a significant dose reduction for patient and staff in this type of radiological intervention.     

Search deficits in neglect patients are dependent on size of the visual scene.

Patients with hemispatial neglect are impaired at moving their attention to a target on the contralesional display side. In the present study, visual display area was varied independently of the number of items displayed within the area. Patients searched for the absence of a simple visual feature in displays that produce serial search performance in normals. The contralesional delay was enhanced for stimulus arrays that were distributed over a larger display area, which suggests that neglect is more severe when attention has to be moved over a larger distance. The directional disengage deficit in neglect therefore depends on the target's relative position within a display, the number of ipsilesional items competing for attention, and the distance of the contralesional attention movements. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How to overcome the detrimental effects of noise in social interaction: The benefits of generosity.

Interpersonal misunderstanding is often rooted in noise, or discrepancies between intended and actual outcomes for an interaction partner due to unintended errors (e.g., not being able to respond to an E-mail because of a local network breakdown). How can one effectively cope with noise in social dilemmas, situations in which self-interest and collective interests are conflicting? Consistent with hypotheses, the present research revealed that incidents of noise exert a detrimental effect on level of cooperation when a partner follows strict reciprocity (i.e., tit for tat) but that this effect can be overcome if a partner behaves somewhat more cooperatively than the actor did in the previous interaction (i.e., tit for tat plus 1). Also, when noise was present, tit for tat plus 1 elicited greater levels of cooperation than did tit for tat, thereby underscoring the benefits of adding generosity to reciprocity in coping with noise in social dilemmas. The Discussion outlines implications of the present work for theories focusing on self-presentation and attribution, communication, and trust and prorelationship behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A tribosphenic mammal from the Mesozoic of Australia

A small, well-preserved dentary of a tribosphenic mammal with the most posterior premolar and all three molars in place has been found in Aptian (Early Cretaceous) rocks of southeastern Australia. In most respects, dental and mandibular anatomy of the specimen is similar to that of primitive placental mammals. With the possible exception of a single tooth reported as Eocene in age, terrestrial placentals are otherwise unknown in Australia until the Pliocene. This possible Australian placental is similar in age to Prokennalestes from the late Aptian/early Albian Khoboor Beds of Mongolia, the oldest currently accepted member of the infraclass Placentalia.     

Upgrading system-oriented ecotoxicological research

In the 1990s the Dutch government expressed the need to investigate the impacts of diffuse pollution at (sub)-ecosystem levels. The resulting Netherlands Stimulation Programme on System-oriented Ecotoxicological Research (SSEO programme) ran from 1998 to 2006. Its primary objective was to assess the impacts of low- to medium-level, diffuse, multiple contaminations on ecosystems. The research results were intended as underpinning for policies on environmental, conservation and nature issues. Research was carried out at three sites that were selected because of their importance for nature management and the presence of diffuse contamination. These sites were: a river meadow/floodplain area (Afferdensche en Deestsche Waarden), an estuarine reed-land area (Biesbosch) and an area of lowland peat soils that had been contaminated with urban waste in past centuries (De Ronde Venen).This introductory paper describes the set-up of the programme, the types of diffuse contamination, the interactions between pollutants and other stress factors, the various methodologies used to integrate the effects on (sub)ecosystem level, and the consequences for formulating policies for and the management of these types of locations.The results of the programme are diverse and complicated and show how difficult it is to draw firm, unambiguous, generic conclusions about the effects at the ‘total’ ecosystem level. It is however, possible to draw conclusions about effects on major components of ecosystems:

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The distribution of contaminants, both from a spatial, chemical and ecotoxicological point of view, plays a decisive role in actual effect levels. Even when total contaminant loads are high, such as in estuarine and floodplain areas, bioavailability may be so low that the actual effects are limited. The irregular, heterogeneous, spatial distribution of contaminants in the soil further complicates effect studies, impact assessments and monitoring.

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Various stress factors, other than contaminants, both natural and anthropogenic, also play a role. The negative effect of the repeated inundation of floodplain areas, for instance, greatly interferes with the impact of contaminants in the lower soil layers.

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A major problem is to find a method to extrapolate the observations from individual and population levels to the ecosystem level. In addition to traditional food-chain models and similar approaches, the potential of other, not yet extensively explored, ecosystem interaction mechanisms is discussed.

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Finally, the results have to be interpreted from a policy point of view, both for national soil policies and for implementing the EU Soil Strategy regulations.

     

Synthesis and properties of size-expanded DNAs: toward designed, functional genetic systems

We describe the design, synthesis, and properties of DNA-like molecules in which the base pairs are expanded by benzo homologation. The resulting size-expanded genetic helices are called xDNA ("expanded DNA") and yDNA ("wide DNA"). The large component bases are fluorescent, and they display high stacking affinity. When singly substituted into natural DNA, they are destabilizing because the benzo-expanded base pair size is too large for the natural helix. However, when all base pairs are expanded, xDNA and yDNA form highly stable, sequence-selective double helices. The size-expanded DNAs are candidates for components of new, functioning genetic systems. In addition, the fluorescence of expanded DNA bases makes them potentially useful in probing nucleic acids.     

Analysing the effectiveness of renewable energy supporting policies in the European Union

With several mid-term policies in place to support the development of renewables, the European Union (EU) seems on its way to increasing the share of renewable energy to the targeted 12% by the year 2010. It is however, yet unclear how effective these policies are, which technologies will see the largest growth and which countries will indeed be able to meet their targets. This article discusses a monitoring protocol that was developed to monitor this effectiveness and judge whether targets will be met. In a step-wise approach policy instruments are characterised and analysed, leading to a quantitative assessment of the likely growth in renewable energy production for each individual technology and country in case no policy changes occur. Applying this monitoring protocol at the EU-level we show that with the current policies in place renewable energy production will reach a share of 8–10% in 2010, and the share of electricity production will reach a level of 15–18% of total electricity consumption, whereas the target is 22.5%. Additional policies are clearly needed to achieve the ambitious targets set.