175 research outputs found
Familiar scars: an exploration of the biological correlates of child maltreatment in an extended family design
The aim of this dissertation was to explore the biological correlates of child maltreatment in a family context. We used an extended family design to investigate intergenerational transmission of child maltreatment, the role of heritability in child maltreatment, and the association of child maltreatment with parent-childresting state connectome similarity (RScs), hair glucocorticoids, and BMI. In sum, these studies show that child maltreatment (in particular abuse) runs in families– partly because of genetic factors, partly because of environmental factors – is associated with less dyadic RScs, and higher long-term hair cortisone levels andweight. Thus, four biological systems – genetic, neural activation, endocrine, metabolic – are implicated in child maltreatment at a family level.Development Psychopathology in context: famil
Experimental investigations on the fatigue resistance of automatically welded tubular X-joints for jacket support structures
The development within the offshore wind sector towards more powerful turbines combined with increasing water depth for new wind parks is challenging both the designer as well as the manufacturer of bottom fixed support structures. Besides XL-monopiles, the market developed an innovative and economic jacket support structure which is based on automatically manufactured tubular joints combined with standardized pipes. Besides the improvements for a serial manufacturing process the automatically welded tubular joints show a great potential in terms of fatigue resistance e.g. due to a smooth weld geometry without sharp notches. However, these benefits are not considered yet within the fatigue design process of automatically manufactured jacket substructures according to current standards due to the lack of suitable S-N curves. Therefore, 32 axial fatigue tests on single and double-sided automatically welded tubular X-joints have been performed to determine a new hot spot stress related S-N curve. Based on these constant amplitude fatigue tests a new S-N curve equal to a FAT 126 curve was computed which implicitly includes the benefits of the automatically welding procedure. © Published under licence by IOP Publishing Ltd
Experimental investigations on the fatigue resistance of automatically welded tubular X-joints for jacket support structures
The development within the offshore wind sector towards more powerful turbines combined with increasing water depth for new wind parks is challenging both the designer as well as the manufacturer of bottom fixed support structures. Besides XL-monopiles, the market developed an innovative and economic jacket support structure which is based on automatically manufactured tubular joints combined with standardized pipes. Besides the improvements for a serial manufacturing process the automatically welded tubular joints show a great potential in terms of fatigue resistance e.g. due to a smooth weld geometry without sharp notches. However, these benefits are not considered yet within the fatigue design process of automatically manufactured jacket substructures according to current standards due to the lack of suitable S-N curves. Therefore, 32 axial fatigue tests on single and double-sided automatically welded tubular X-joints have been performed to determine a new hot spot stress related S-N curve. Based on these constant amplitude fatigue tests a new S-N curve equal to a FAT 126 curve was computed which implicitly includes the benefits of the automatically welding procedure
Effects of chronic sleep restriction on the brain functional network, as revealed by graph theory
Sleep is a complex and dynamic process for maintaining homeostasis, and a lack of sleep can disrupt whole-body functioning. No organ is as vulnerable to the loss of sleep as the brain. Accordingly, we examined a set of task-based functional magnetic resonance imaging (fMRI) data by using graph theory to assess brain topological changes in subjects in a state of chronic sleep restriction, and then identified diurnal variability in the graph-theoretic measures. Task-based fMRI data were collected in a 1.5T MR scanner from the same participants on two days: after a week of fully restorative sleep and after a week with 35% sleep curtailment. Each day included four scanning sessions throughout the day (at approximately 10:00 AM, 2:00 PM, 6:00 PM, and 10:00 PM). A modified spatial cueing task was applied to evaluate sustained attention. After sleep restriction, the characteristic path length significantly increased at all measurement times, and small-worldness significantly decreased. Assortativity, a measure of network fault tolerance, diminished over the course of the day in both conditions. Local graph measures were altered primarily across the limbic system (particularly in the hippocampus, parahippocampal gyrus, and amygdala), default mode network, and visual network
Relativistic quantum chemistry on quantum computers
Last years witnessed a remarkable interest in application of quantum
computing for solving problems in quantum chemistry more efficiently than
classical computers allow. Very recently, even first proof-of-principle
experimental realizations have been reported. However, so far only the
non-relativistic regime (i.e. Schroedinger equation) has been explored, while
it is well known that relativistic effects can be very important in chemistry.
In this letter we present the first quantum algorithm for relativistic
computations of molecular energies. We show how to efficiently solve the
eigenproblem of the Dirac-Coulomb Hamiltonian on a quantum computer and
demonstrate the functionality of the proposed procedure by numerical
simulations of computations of the spin-orbit splitting in the SbH molecule.
Finally, we propose quantum circuits with 3 qubits and 9 or 10 CNOTs, which
implement a proof-of-principle relativistic quantum chemical calculation for
this molecule and might be suitable for an experimental realization
Yang-Baxter equation and reflection equations in integrable models
The definitions of the main notions related to the quantum inverse scattering
methods are given. The Yang-Baxter equation and reflection equations are
derived as consistency conditions for the factorizable scattering on the whole
line and on the half-line using the Zamolodchikov-Faddeev algebra. Due to the
vertex-IRF model correspondence the face model analogue of the ZF-algebra and
the IRF reflection equation are written down as well as the -graded and
colored algebra forms of the YBE and RE.Comment: 21 pages, Latex, Lectures in Schladming school of theoretical physics
(March 1995
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
Wavelet Neural Networks: A Practical Guide
Wavelet networks (WNs) are a new class of networks which have been used with great success in a wide range of application. However a general accepted framework for applying WNs is missing from the literature. In this study, we present a complete statistical model identification framework in order to apply WNs in various applications. The following subjects were thorough examined: the structure of a WN, training methods, initialization algorithms, variable significance and variable selection algorithms, model selection methods and finally methods to construct confidence and prediction intervals. In addition the complexity of each algorithm is discussed. Our proposed framework was tested in two simulated cases, in one chaotic time series described by the Mackey-Glass equation and in three real datasets described by daily temperatures in Berlin, daily wind speeds in New York and breast cancer classification. Our results have shown that the proposed algorithms produce stable and robust results indicating that our proposed framework can be applied in various applications
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
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
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