Burstiness predictions based on rough network traffic measurements

To dimension network links, such that they will not become QoS bottle- necks, the peak rate on these links should be known. To measure these peaks on sufficiently small time scales, special measurement tools are needed. Such tools can be quite expensive and complex. Therefore network operators often rely on more cheap, standard tools, like MRTG, which were designed to measure average traffic rates (m) on time scales such as 5 minutes. For estimating the peak traffic rate (p), operators often use simple rules, such as p = α · m. In this paper we describe measurements that we have performed to investigate how well this rule describes the relation between peak and average traffic rate. In addition, we pro- pose some more advanced rules, and compare these to the simple rule mentioned above. The analyses of our measurements, which have been performed on differ- ent kinds of networks, show that our advanced rules more adequately describe the relation between peak and average traffic rate

Nitrate in upper groundwater on farms under tillage as affected by fertilizer use, soil type and groundwater table

Indicators are needed to check whether policies on protection of groundwater are effective and if regulations are complied with. We evaluated various indicators at different scales, both in space and in time, and at different degrees of complexity. Groundwater was sampled on 34 arable farms for 3 years. Nitrate concentration in upper groundwater was low on clay soil. On sandy soil, peat layers reduced the nitrate concentration with about 80 mg/l on average. Sandy soils with high groundwater tables had nitrate concentrations that were less than half of those at sandy soils with low groundwater tables. The relationship between different fertilization variables and nitrate in groundwater was investigated for sandy soils without peat layers. N surplus poorly correlated with nitrate concentrations in groundwater when individual sampling points were studied, but clearly increased when data were averaged at the farm level. Soil mineral nitrogen correlated best with nitrate concentrations in groundwater. The relationships show that especially on well drained soil drastic measures will be inevitable to reach good water quality

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

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

Parents’ experiences of childhood abuse and neglect are differentially associated with behavioral and autonomic responses to their offspring

Although childhood maltreatment has been shown to compromise adaptive parental behavior, little is known what happens in terms of physiological regulation when parents with a history of childhood maltreatment interact with their offspring. Using a sample of 229 parents (131 women), the present study examined whether childhood maltreatment experiences are associated with parents’ behavioral and autonomic responses while resolving conflict with their offspring. Self‐reported experienced child maltreatment was measured using a questionnaire assessing abuse and neglect. Parents (Mage = 52.7 years, rangeage = 26.6–88.4 years) and their offspring (Mage = 24.6 years, rangeage = 7.5–65.6 years) participated in a videotaped parent–offspring conflict interaction task. Parental warmth, negativity, and emotional support were coded. In addition, their pre‐ejection period and respiratory sinus arrhythmia were measured as indicators of underlying sympathetic and parasympathetic nervous system reactivity, respectively. Findings demonstrated that experiences of abuse and neglect were associated with behavioral and physiological responses in different ways. Separating these two types of maltreatment in research and in clinical practice might be important

Parent-child agreement on parent-to-child maltreatment

FSW - Self-regulation models for health behavior and psychopathology - ou

Linking internalizing and externalizing problems to warmth and negativity in observed dyadic parent-offspring communication

Stress and Psychopatholog

Parents’ experiences of childhood abuse and neglect are differentially associated with behavioral and autonomic responses to their offspring

Although childhood maltreatment has been shown to compromise adaptive parental behavior, little is known what happens in terms of physiological regulation when parents with a history of childhood maltreatment interact with their offspring. Using a sample of 229 parents (131 women), the present study examined whether childhood maltreatment experiences are associated with parents’ behavioral and autonomic responses while resolving conflict with their offspring. Self‐reported experienced child maltreatment was measured using a questionnaire assessing abuse and neglect. Parents (Mage = 52.7 years, rangeage = 26.6–88.4 years) and their offspring (Mage = 24.6 years, rangeage = 7.5–65.6 years) participated in a videotaped parent–offspring conflict interaction task. Parental warmth, negativity, and emotional support were coded. In addition, their pre‐ejection period and respiratory sinus arrhythmia were measured as indicators of underlying sympathetic and parasympathetic nervous system reactivity, respectively. Findings demonstrated that experiences of abuse and neglect were associated with behavioral and physiological responses in different ways. Separating these two types of maltreatment in research and in clinical practice might be important.Stress and Psychopatholog

Not the root of the problem: Hair cortisol and cortisone do not mediate the effect of child maltreatment on BMI

Stress and Psychopatholog

Not the Root of the Problem—Hair Cortisol and Cortisone Do Not Mediate the Effect of Child Maltreatment on Body Mass Index

Background: Experiencing maltreatment during childhood exerts substantial stress on the child and increases the risk for overweight and obesity later in life. The current study tests whether hair cortisol—a measure of chronic stress—and its metabolite cortisone mediate the relation between abuse and neglect on the one hand, and body mass index (BMI) on the other. Method: The sample consisted of 249 participants aged 8 to 87 years (M = 36.13, SD = 19.33). We collected data on child abuse and neglect using questionnaires, measured cortisol and cortisone concentrations in hair, and BMI. In a structural model, the effects of abuse and neglect on hair cortisol, hair cortisone, and BMI were tested, as well as the covariance between hair cortisol and BMI, and hair cortisone and BMI. Results: Within the sample, 23% were overweight but not obese and 14% were obese. Higher levels of experienced abuse were related to higher cortisone concentrations in hair (β = 0.24, p <.001) and higher B