An anharmonic force field for SO3

An anharmonic force field for SO3 based on the valence force model has been investigated. The results of extending the model to include some further estimated cubic interaction potential constants have also been investigated. The phenomenological parameters calculated from both model force fields agree with those few values which have been experimentally determined. A calculation of the inertia defect has been made, and thus the value of C0 has been determined. The equilibrium structure has been determined to be: re = 1.4184 ± 0.0010 Å.

From a discrete to a continuum model of cell dynamics in one dimension

Multiscale modeling is emerging as one of the key challenges in mathematical biology. However, the recent rapid increase in the number of modeling methodologies being used to describe cell populations has raised a number of interesting questions. For example, at the cellular scale, how can the appropriate discrete cell-level model be identified in a given context? Additionally, how can the many phenomenological assumptions used in the derivation of models at the continuum scale be related to individual cell behavior? In order to begin to address such questions, we consider a discrete one-dimensional cell-based model in which cells are assumed to interact via linear springs. From the discrete equations of motion, the continuous Rouse [P. E. Rouse, J. Chem. Phys. 21, 1272 (1953)] model is obtained. This formalism readily allows the definition of a cell number density for which a nonlinear "fast" diffusion equation is derived. Excellent agreement is demonstrated between the continuum and discrete models. Subsequently, via the incorporation of cell division, we demonstrate that the derived nonlinear diffusion model is robust to the inclusion of more realistic biological detail. In the limit of stiff springs, where cells can be considered to be incompressible, we show that cell velocity can be directly related to cell production. This assumption is frequently made in the literature but our derivation places limits on its validity. Finally, the model is compared with a model of a similar form recently derived for a different discrete cell-based model and it is shown how the different diffusion coefficients can be understood in terms of the underlying assumptions about cell behavior in the respective discrete models.

Infrared actuation in aligned polymer-nanotube composites

Rubber composites containing multiwalled carbon nanotubes have been irradiated with near-infrared light to study their reversible photomechanical actuation response. We demonstrate that the actuation is reproducible across differing polymer systems. The response is directly related to the degree of uniaxial alignment of the nanotubes in the matrix, contracting the samples along the alignment axis. The actuation stroke depends on the specific polymer being tested; however, the general response is universal for all composites tested. We conduct a detailed study of tube alignment induced by stress and propose a model for the reversible actuation behavior based on the orientational averaging of the local response. The single phenomenological parameter of this model describes the response of an individual tube to adsorption of low-energy photons; its experimentally determined value may suggest some ideas about such a response.

A variational method for the calculation of spin-rovibronic energy levels of any triatomic molecule in an electronic triplet state

The triatomic spin-rovibronic variational code RVIB3 has been extended to include the effect of two uncoupled electrons, for both (3)Sigma(-) and (3)Pi (Renner-Teller) electronic states. The spin-orbital-rotational kinetic energy is included in the usual way, via terms (J+L+S). The phenomenological terms AL.S and lambda 2/3(3S(z)(2)) are introduced to reproduce the 3 spin-orbit and spin-spin splittings, respectively. Calculations are performed to evaluate the spin-rovibronic energy levels of CCO (X) over tilde (3) Sigma(-) and CCO (A) over tilde (3) Pi for which the Born-Oppenheimer potentials are derived from high-accuracy ab initio calculations.

Architect and user interaction: The spoken representation of form and functional meaning

The paper is an investigation of the exchange of ideas and information between an architect and building users in the early stages of the building design process before the design brief or any drawings have been produced. The purpose of the research is to gain insight into the type of information users exchange with architects in early design conversations and to better understand the influence the format of design interactions and interactional behaviours have on the exchange of information. We report an empirical study of pre-briefing conversations in which the overwhelming majority of the exchanges were about the functional or structural attributes of space, discussion that touched on the phenomenological, perceptual and the symbolic meanings of space were rare. We explore the contextual features of meetings and the conversational strategies taken by the architect to prompt the users for information and the influence these had on the information provided. Recommendations are made on the format and structure of pre-briefing conversations and on designers' strategies for raising the level of information provided by the user beyond the functional or structural attributes of space.

The effect of postnatal depression on mother-infant interaction, infant response to the still-face perturbation, and performance on an instrumental learning task

A representative community sample of primiparous depressed women and a nondepressed control group were assessed while in interaction with their infants at 2 months postpartum. At 3 months, infants were assessed on the Still-face perturbation of face to face interaction, and a subsample completed an Instrumental Learning paradigm. Compared to nondepressed women, depressed mothers' interactions were both less contingent and less affectively attuned to infant behavior. Postnatal depression did not adversely affect the infant's performance in either the Still-face perturbation or the Instrumental Learning assessment. Maternal responsiveness in interactions at 2 months predicted the infant's performance in the Instrumental Learning assessment but not in the Still-face perturbation. The implications of these findings for theories of infant cognitive and emotional development are discussed.

Attentional bias in eating disorders

Objective: To examine the relationship between eating disorders and attentional biases. Method: The first study comprised 23 female patients with clinical eating disorders, women with high levels of anxiety (n = 19), and three female normal control groups comprising low (n = 31), moderate (n = 21), or high levels of shape concern (n 23). The second study comprised 82 women with clinical eating disorders and 44 healthy controls. All participants completed measures of eating disorder psychopathology and completed a modified pictorial dot-probe task. Results: In the first study, biases were found for negative eating and neutral weight pictures, and for positive eating pictures in women with eating disorders; these biases were greater than those found in anxious and normal controls. The second study replicated these findings and biases were also found for negative and neutral shape stimuli. Conclusion: It is concluded that future research should establish whether such biases warrant specific therapeutic interventions. (c) 2007 by Wiley Periodicals, Inc.

The effects of pre- and postnatal depression in fathers: a natural experiment comparing the effects of exposure to depression on offspring

Background: Depression in fathers in the postnatal period is associated with an increased risk of behavioural problems in their offspring, particularly for boys. The aim of this study was to examine for differential effects of depression in fathers on children's subsequent psychological functioning via a natural experiment comparing prenatal and postnatal exposure. Methods:In a longitudinal population cohort study (the Avon Longitudinal Study of Parents and Children (ALSPAC)) we examined the associations between depression in fathers measured in the prenatal and postnatal period (measured using the Edinburgh Postnatal Depression Scale), and later behavioural/emotional and psychiatric problems in their children, assessed at ages 31/2 and 7 years. Results: Children whose fathers were depressed in both the prenatal and postnatal periods had the highest risks of subsequent psychopathology, measured by total problems at age 31/2 years (Odds Ratio 3.55; 95% confidence interval 2.07, 6.08) and psychiatric diagnosis at age 7 years (OR 2.54; 1.19, 5.41). Few differences emerged when prenatal and postnatal depression exposure were directly compared, but when compared to fathers who were not depressed, boys whose fathers had postnatal depression only had higher rates of conduct problems aged 31/2 years (OR 2.14; 1.22, 3.72) whereas sons of the prenatal group did not (OR 1.41; .75, 2.65). These associations changed little when controlling for maternal depression and other potential confounding factors. Conclusions: The findings of this study suggest that the increased risk of later conduct problems, seen particularly in the sons of depressed fathers, maybe partly mediated through environmental means. In addition, children whose fathers are more chronically depressed appear to be at a higher risk of emotional and behavioural problems. Efforts to identify the precise mechanisms by which transmission of risk may occur should be encouraged to enable the development of focused interventions to mitigate risks for young children.

Safety behaviour: a reconsideration

There is ample evidence that the use of safety behaviour can interfere with the progress of therapy, particularly if exposure is involved. As a result, it is widely asserted that safety behaviour is anti-therapeutic. However, an unqualified rejection of safety behaviour should be reconsidered because we now have theoretical justification, experimental evidence and clinical observations showing that the judicious use of safety behaviour, especially in the early stages of treatment, can be facilitative. Experiments in which escape behaviour facilitated fear reduction, and others in which the use of safety gear facilitated fear reduction, are reviewed. It also appears that safety behaviour does not necessarily prevent disconfirmatory experiences. We propose that additional investigations of the judicious use of safety behaviour will help to elucidate therapeutic uses of safety behaviour in the treatment of anxious and related types of psychopathology. (c) 2007 Elsevier Ltd. All rights reserved.

Children's representation of family mealtime in the context of maternal eating disorders

Background Recent research provides evidence for specific disturbance in feeding and growth in children of mothers with eating disorders. Aim To investigate the impact of maternal eating disorders during the post-natal year on the internal world of children, as expressed in children's representations of self and their mother in pretend mealtime play at 5 years of age. Methods Children of mothers with eating disorders (n = 33) and a comparison group (n = 24) were videotaped enacting a family mealtime in pretend play. Specific classes of children's play representations were coded blind to group membership. Univariate analyses compared the groups on representations of mother and self. Logistic regression explored factors predicting pretend play representations. Results Positive representations of the mother expressed as feeding, eating or body shape themes were more frequent in the index group. There were no other significant group differences in representations. In a logistic regression analysis, current maternal eating psychopathology was the principal predictor of these positive maternal representations. Marital criticism was associated with negative representations of the mother. Conclusions These findings suggest that maternal eating disorders may influence the development of a child's internal world, such that they are more preoccupied with maternal eating concerns. However, more extensive research on larger samples is required to replicate these preliminary findings.

Socioemotional development in adolescents at risk for depression: the role of maternal depression and attachment style

We examined the impact on adolescent socioemotional functioning of maternal postnatal depression (PND) and attachment style. We also investigated the role of earlier aspects of the child's development-attachment in infancy, and 5-year representations of family relationships. Ninety-one mother-child pairs, recruited in the postnatal period, were followed tip at 13 years. Adolescents were interviewed about their friendships, and their level of emotional sensitivity and maturity were rated. Emotional sensitivity was heightened in girls whose mothers experienced PND; notably, its occurrence was also linked to insecure attachment in infancy and raised awareness of emotional components of family relationships at 5 years. High emotional sensitivity was also associated with adolescent depressed mood. Raised social maturity was predicted by a secure maternal attachment style and, for girls, by exposure to maternal PND. Precursors of adolescent social maturity were evident in the narrative coherence of 5-year family representations. Higher social maturity in the friendship interview was also associated with overall good adjustment.

Processing biases in eating disorders: the impact of temporal factors

Objective: Previous research has indicated that temporal factors [specifically, the duration of interstimulus intervals (ISI) during a threat processing task] may influence the nature of processing biases exhibited in nonclinical populations with some degree of eating disorder psychopathology (Meyer et al., Int J Eat Disord, 27, 405-410, 2000). The current study aimed to test this hypothesis by investigating attentional biases for eating-disorder-relevant images and irrelevant visual images (animals) in patients with eating disorders (n = 23) and psychiatric (n = 19) and nonpsychiatric (n = 65) controls. Method: A dot probe task was modified from previous research (Shafran et al., Int Eat Disord, 40, 369-380, 2007), whereby an original ISI of 500 ms was increased to 2.000 ms. Results: Patients with an eating disorder continued to display a bias in the processing of weight stimuli. However, biases noted in previous research for shape and weight stimuli disappeared when the ISI duration was increased in this way. Conclusion: These findings highlight the importance of temporal factors in whether processing biases are displayed and may point to ways in which biases actually work in this population. However, further research is warranted. (C) 2008 by Wiley Periodicals, Inc.

There must be more to development of mindreading and metacognition than passing false belief tasks

We argue that while it is a valuable contribution, Carruthers' Model may be too restrictive to elaborate our understanding of the development of mindreading and metacognition, or to enrich our knowledge of individual differences and psychopathology. To illustrate, we describe pertinent examples where there may be a critical interplay between primitive social-cognitive processes and emerging self-attributions.

Exposure to postnatal depression predicts elevated cortisol in adolescent offspring

Background. Animal research shows that early adverse experience results in altered glucocorticoid levels in adulthood, either raised basal levels or accentuated responses to stress. If a similar phenomenon operates in humans, this suggests a biological mechanism whereby early adversity might transmit risk for major depression, glucocorticoid elevations being associated with the development of this disorder. Methods. We measured salivary cortisol at 8:00 Am and 8:00 Pm over 10 days in 13-year-old adolescents who had (n = 48) or bad not (n = 39) been exposed to postnatal maternal depression. Results: Maternal postnatal depression was associated with higher, more variable morning cortisol in offspring, a pattern previously found to predict major depression. Conclusions. Early adverse experiences might alter later steroid levels in humans. Because maternal depression confers added risk for depression to children, these alterations might provide a link between early events and later psychopathology.

'They did not have a word': the parental quest to locate a 'true sex' for their intersex children

Given the paucity of research in this area, the primary aim of this study was to explore how parents of infants with unclear sex at birth made sense of 'intersex'. Qualitative methods were, used (semi-structured interviews, interpretative phenomenological analysis) with 10 parents to generate pertinent themes and provide ideas for further research. Our analysis highlights the fundamental shock engendered by the uncertain sex status of children, and documents parental struggles to negotiate a coherent sex identity for their children. Findings are discussed in light of the rigid two-sex system which pervades medicine and everyday life, and we argue that greater understanding of the complexity of sex and gender is required in order to facilitate better service provision and, ultimately, greater informed consent and parental participation regarding decisions about their children's status.