Experimental study of launched ion-acoustic waves in a plasma using continuous wave CO2 laser scattering

A study of coherent density fluctuations in a low density plasma using continuous wave CO/sub 2/ laser scattering diagnostics is reported. A simple and direct description of collective scattering theory from monochromatic electrostatic waves is presented. The diagnostic technique is described in detail and its performance is analyzed. Experimental results on externally launched ion-acoustic waves are presented and it is demonstrated that accurate measurements of certain plasma parameters are possibl

Salivary cortisol: a possible biomarker in evaluating stress and effects of interventions in young foster children?

Contains fulltext : 136764.pdf (publisher's version ) (Closed access)Young foster children undergo an early separation from their caregiver(s) and often experience severe stress before placement. However, a considerable part of the children do not show apparent signs of distress, making it difficult for the foster carer to be aware of the amount of stress in their foster child. Potential evidence for using salivary cortisol levels as a dimension to evaluate the amount of stress in young foster children is reviewed. Moreover, the applicability of salivary cortisol in the evaluation of stress-reducing interventions for young foster children is discussed. A systematic review was performed using the databases Medline, Psychinfo, Embase, Ebscohost, and Academic Search Premier. Nine studies were traced in which salivary cortisol was used to measure stress in children placed in family foster care or in adoptive families. Stress in general but also neglect, early loss of a caregiver, a younger age at first placement, and a higher number of placements were associated with an altered hypothalamic-pituitary-adrenal (HPA) axis function in foster children. Moreover, four studies on the effect of stress-reducing interventions on HPA-axis functioning of young foster children were found. These studies suggest that caregiver-based interventions can actually help to normalize the HPA-axis function in foster children, and that such changes co-occur with improved behavioral functioning. Although the results from the papers discussed in this review suggest that diurnal cortisol with a wake up and a bedtime measurement may be a relevant tool to evaluate stress in young foster children, this cannot yet be concluded from the present studies, because statistical data from the studies on foster care and adoption in this review were not robust and researchers used different methods to collect the salivary cortisol. Still, it is noteworthy that all studies did find the same pattern of reduced levels in relation to chronic stress (caused by maltreatment and neglect of the child)

Searching for effective interventions for young foster children under stress:A meta-analysis

Foster children experience a lot of stress because of their life histories and changes in their family circumstances, such as foster care placement. It is important that foster parents recognize the early signs of stress in foster children and learn how to act in a non-threatening and understanding manner. Family-based interventions may help in this. In this paper, we report on a meta-analysis of studies (n= 19) of the effectiveness of such interventions. All studies used a pre-test/post-test design. Both problem behaviour in foster children and the parenting skills of foster parents improved by 30%; however, none of the interventions were specifically intended to help young children

Salivary cortisol:A possible biomarker in evaluating interventions on stress reduction in young foster children

Young foster children undergo an early separation from their caregiver(s) and often experience severe stress before placement. However, a considerable part of the children do not show apparent signs of distress, making it difficult for the foster carer to be aware of the amount of stress in their foster child. Potential evidence for using salivary cortisol levels as a dimension to evaluate the amount of stress in young foster children is reviewed. Moreover, the applicability of salivary cortisol in the evaluation of stress-reducing interventions for young foster children is discussed. A systematic review was performed using the databases Medline, Psychinfo, Embase, Ebscohost, and Academic Search Premier. Nine studies were traced in which salivary cortisol was used to measure stress in children placed in family foster care or in adoptive families. Stress in general but also neglect, early loss of a caregiver, a younger age at first placement, and a higher number of placements were associated with an altered hypothalamic-pituitary-adrenal (HPA) axis function in foster children. Moreover, four studies on the effect of stress-reducing interventions on HPA-axis functioning of young foster children were found. These studies suggest that caregiver-based interventions can actually help to normalize the HPA-axis function in foster children, and that such changes co-occur with improved behavioral functioning. Although the results from the papers discussed in this review suggest that diurnal cortisol with a wake up and a bedtime measurement may be a relevant tool to evaluate stress in young foster children, this cannot yet be concluded from the present studies, because statistical data from the studies on foster care and adoption in this review were not robust and researchers used different methods to collect the salivary cortisol. Still, it is noteworthy that all studies did find the same pattern of reduced levels in relation to chronic stress (caused by maltreatment and neglect of the child)

The developing relationship between recently placed foster infants and toddlers and their foster carers: Do demographic factors, placement characteristics and biological stress markers matter?

Background Infants and toddlers often react to a foster family placement with avoidant behavior. Foster carers may interpret this as if the child is adapting quite well to the new family. This misunderstanding may lead to stress in the child and create a risk for an enduring relationship. Objectives To investigate the quality of newly formed relationships between recently placed infants and toddlers and their foster carers. Methods In a sample of 123 foster families interactions between foster children, aged between 6 weeks and 42 months, and foster carers were videotaped and coded according to a semi-structured procedure (Emotional Availability Scales; EAS). Foster carers were asked to fill in a parenting stress scale (NOSI-R). Children's case files were studied for demographic and placement characteristics. Samples of children's salivary cortisol were taken. Results 70-80 % of the children scored low on EAS responsiveness and involvement. The majority of foster carers did not perceive stress in the relation with their foster child (NOSI-R). The children who gave rise to relational stress tended to show higher levels of salivary cortisol. Conclusions If foster carers do recognise relational stress, this may indicate stress in the child. It is important that foster carers learn to recognise this shut off behavior as a possible risk factor because it may lead to maladaptation and chronic stress in young foster children. Implications for research and practice are discussed

Enhanced small scale turbulence oscillations correlated to sawtooth relaxations in the TEXTOR tokamak

SIGLECopy held by FIZ Karlsruhe; available from UB/TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman