A periodic enhancement of the microturbulence level by sawtooth relaxations has been detected by CO2 laser forward scattering in the TEXTOR tokamak. This feature is reproduced quantitatively by a heat transport code in which the anomalous electron transport coefficient is calculated self-consistently, following a theoretical model of the saturation of the dissipative trapped electron instability. The code also predicts a strong modulation of the heat flux throughout the plasma and a strong 'profile consistency' as demonstrated elsewhere by continuous temperature measurements. A simple interpretation of these results is given. The calculated global plasma parameters, such as the energy confinement time and the loop voltage, are in good agreement with the measured values.

CO, laser collective scattering has been used on TEXTOR to measure electron density fluctuation amplitude ff2 ( , f , k ) in the parameter range 50 kHz < .f < 3.5 MHz and 3 cm-' c k < 130 cm-' using both forward and far-forward scattering techniques. Measurements are presented for ohmically heated plasmas and for discharges with ICRF auxiliary heating. Frequency spectra have maxima in the range 100 kHz < , / , , , < 400 kHz and decay asf-O with 1.5 < < 3.5 depending on plasma conditions. The frequency of maximum fluctuation amplitude and the spectral width in frequency at fixed k scales linearly with electron temperature. Wave number spectra decaying as k-" are observed, with CI evolving during the plasma discharge and being approximately equal to 4 during the steady-state phase of the discharge. The wave number component of maximum amplitude obtained from far forward scattering measurements lies in the interval 7 cm-l < k,,, < 10 cm-'. A density scaling experiment shows little dependence of thc normalized turbulence level associated with one observation wave number on the gross energy confinement time, but indicates a strong effect of the electron temperature on (A),/n, for a fixed value of T ~. Strong correlations between sawtooth oscillations and turbulence levels were measured using small-k scattering. Also, changes in the fluctuation level during ICRF heating were correlated to changes in the electron density profile, giving (A'),, -iL,j-5, where L, is the density scale length for 0.45 < r n < 0.65. No reproducible variation of fluctuation level with ICRF heating power could be established.

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).

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 (<4 years) to cope with stress. The importance of interventions for young foster children is discussed, as well as the necessary elements these interventions should include.

The developing relationship between recently placed foster infants and toddlers and their foster carers: Do demographic factors, placement characteristics and biological stress markers matter? Children and Youth Services Review, 58,[219][220][221][222][223][224][225][226].