Precisie rechtgeleiding werktuig met RTK GPS : een onderzoek naar verschillende stuursystemen op basis van nauwkeurige GPS systemen

Porojectnummer 325003150

Kleine landschapselementen in de Schermer; resultaten van een proefinventarisatie (supplement bij Alterra-rapport 897)

Voor het opzetten van een Meetnet Kleine Landschapselementen is in 2003 een pilotstudie uitgevoerd. Dit rapport geeft de resultaten van de proefinventarisatie in de Schermer. In dit gebied is de proefinventarisatie in de winterperiode uitgevoerd. Er is extra aandacht besteed aan de erfbeplantingen

Pass it on? The neural responses to rejection in the context of a family study on maltreatment

Rejection by parents is an important aspect of child maltreatment. Altered neural responses to social rejection have been observed in maltreated individuals. The current study is the first to examine the impact of experienced and perpetrated abuse and neglect on neural responses to social exclusion by strangers versus family using a multigenerational family design, including 144 participants. The role of neural reactivity to social exclusion in the intergenerational transmission of maltreatment was also examined. Exclusion by strangers was especially associated with increased activation in the left insula, while exclusion by a family member was mainly associated with increased activation in the ACC. Neural reactivity to social exclusion by strangers in the insula, ACC and dmPFC, was associated with experienced maltreatment but not with perpetrated maltreatment. In abusive parents, altered neural reactivity during exclusion was found in other brain areas, indicating different neural correlates of experienced and perpetrated maltreatment. Hence, no mechanisms could be identified that are involved in the transmission of maltreatment. Hypersensitivity to social rejection by strangers in neglected individuals underscores the importance to distinguish between effects of abuse and neglect and suggests that the impact of experiencing rejection and maltreatment by your own parents extends beyond the family context.Development Psychopathology in context: famil

An intergenerational family study on the impact of experienced and perpetrated child maltreatment on neural face processing

Altered processing of emotional faces due to childhood maltreatment has repeatedly been reported, and may be a key process underlying the intergenerational transmission of maltreatment. The current study is the first to examine the role of neural reactivity to emotional and neutral faces in the transmission of maltreatment, using a multi-generational family design including 171 participants of 51 families of two generations with a large age range (8–69 years). The impact of experienced and perpetrated maltreatment (abuse and neglect) on face processing was examined in association with activation in the amygdala, hippocampus, inferior frontal gyrus (IFG) and insula in response to angry, fearful, happy and neutral faces. Results showed enhanced bilateral amygdala activation in response to fearful faces in older neglected individuals, whereas reduced amygdala activation was found in response to these faces in younger neglected individuals. Furthermore, while experienced abuse was associated with lower IFG activation in younger individuals, experience of neglect was associated with higher IFG activation in this age group, pointing to potentially differential effects of abuse and neglect and significant age effects. Perpetrated abusive and neglectful behavior were not related to neural activation in any of these regions. Hence, no indications for a role of neural reactivity to emotional faces in the intergenerational transmission of maltreatment were found.Stress and Psychopatholog

Estimation of expiratory time constants via fuzzy clustering

Objective. In mechanically ventilated patients the expiratorytime constant provides information about respiratory mechanics. In thepresent study a new method, fuzzy clustering, is proposed to determine expiratory time constants. Fuzzy clustering differs from other methods since it neither interferes with expiration nor presumes any functional relationship between the variables analysed. Furthermore, time constantbehaviour during expiration can be assessed, instead of an average timeconstant. The time constants obtained with fuzzy clustering are comparedto time constants conventionally calculated from the same expirations. Methods. 20 mechanically ventilated patients, including 10 patients with COPD, were studied. The data of flow, volume and pressure were sampled. From these data, four local linear models were detected by fuzzy clustering. The

Back-flow ripples in troughs downstream of unit bars: Formation, preservation and value for interpreting flow conditions

Back-flow ripples are bedforms created within the lee-side eddy of a larger bedform with migration directions opposed or oblique to that of the host bedform. In the flume experiments described in this article, back-flow ripples formed in the trough downstream of a unit bar and changed with mean flow velocity; varying from small incipient back-flow ripples at low velocities, to well-formed back-flow ripples with greater velocity, to rapidly migrating transient back-flow ripples formed at the greatest velocities tested. In these experiments back-flow ripples formed at much lower mean back-flow velocities than predicted from previously published descriptions. This lower threshold mean back-flow velocity is attributed to the pattern of velocity variation within the lee-side eddy of the host bedform. The back-flow velocity variations are attributed to vortex shedding from the separation zone, wake flapping and increases in the size of, and turbulent intensity within, the flow separation eddy controlled by the passage of superimposed bedforms approaching the crest of the bar. Short duration high velocity packets, whatever their cause, may form back-flow ripples if they exceed the minimum bed shear stress for ripple generation for long enough or, if much faster, may wash them out. Variation in back-flow ripple cross-lamination has been observed in the rock record and, by comparison with flume observations, the preserved back-flow ripple morphology may be useful for interpreting formative flow and sediment transport dynamics