Associations of maternal stress with children's weight-related behaviours: a systematic literature review.

Low adherence to guidelines for weight-related behaviours (e.g. dietary intake and physical activity) among US children underscores the need to better understand how parental factors may influence children's obesity risk. In addition to most often acting as primary caregiver to their children, women are also known to experience greater levels of stress than men. This study systematically reviewed associations between maternal stress and children's weight-related behaviours. Our search returned 14 eligible articles, representing 25 unique associations of maternal stress with a distinct child weight-related behaviour (i.e. healthy diet [n = 3], unhealthy diet [n = 6], physical activity [n = 7] and sedentary behaviour [n = 9]). Overall, findings for the relationship between maternal stress and children's weight-related behaviours were mixed, with no evidence for an association with children's healthy or unhealthy dietary intake, but fairly consistent evidence for the association of maternal stress with children's lower physical activity and higher sedentary behaviour. Recommendations for future research include prioritizing prospective designs, identifying moderators, and use of high-resolution, real-time data collection techniques to elucidate potential mechanisms.

Photon counting statistics for blinking CdSe-ZnS quantum dots: a Lévy walk process.

We analyze photon statistics of blinking CdSe-ZnS nanocrystals interacting with a continuous wave laser field, showing that the process is described by a ballistic Lévy walk. In particular, we show that Mandel's Q parameter, describing the fluctuations of the photon counts, is increasing with time even in the limit of long time. This behavior is in agreement with the theory of Silbey and co-workers (Jung et al. Chem. Phys. 2002, 284, 181), and in contrast to all existing examples where Q approaches a constant, independent of time in the long time limit. We then analyze the distribution of the time averaged intensities, showing that they exhibit a nonergodic behavior, namely, the time averages remain random even in the limit of a long measurement time. In particular, the distribution of occupation times in the on-state compares favorably to a theory of weak ergodicity breaking of blinking nanocrystals. We show how our data analysis yields information on the amplitudes of power-law decaying on and off time distributions, information not available using standard data analysis of on and off time histograms. Photon statistics reveals fluctuations in the intensity of the bright state indicating that it is composed of several states. Photon statistics exhibits a Lévy walk behavior also when an ensemble of 100 dots is investigated, indicating that the strange kinetics can be observed already at the level of small ensembles.

Single-molecule chemical reactions: reexamination of the Kramers approach.

Single-molecule chemical reactions yield insight into fluctuation phenomena that are obscured in the measurement of the ensemble of molecules. Kramers escape problem is investigated here in a framework suitable for single-molecule reactions. In particular we obtain distributions of escape times in simple limiting cases, rather than their mean, and investigate their sensitivity on initial conditions. Rich physical behaviors are observed: sub-Poissonian statistics when the dynamics is only slightly deviating from the Newtonian, super-Poissonian behavior when diffusion is dominating, and Poissonian behavior when Kramers original conditions hold. By varying initial conditions escape time distributions can follow a (usual) exponential or a tau(-3/2) decay, due to regular diffusion. We briefly address experimental results that yield the tau(-3/2) behavior (with cutoffs) and propose that this behavior is universal.

Nonergodicity of blinking nanocrystals and other Lévy-walk processes.

We investigate the nonergodic properties of blinking nanocrystals modeled by a Lévy-walk stochastic process. Using a nonergodic mean field approach we calculate the distribution functions of the time averaged intensity correlation function. We show that these distributions are not delta peaked on the ensemble average correlation function values; instead they are W or U shaped. Beyond blinking nanocrystals our results describe ergodicity breaking in systems modeled by Lévy walks , for example, certain types of chaotic maps and spin dynamics to name a few.

Aging correlation functions for blinking nanocrystals, and other on-off stochastic processes.

Following recent experiments on power law blinking behavior of single nanocrystals, we calculate two-time intensity correlation functions I(t)I(t+t') for these systems. We use a simple two state (on and off) stochastic model to describe the dynamics. We classify possible behaviors of the correlation function and show that aging, e.g., dependence of the correlation function on age of process t, is obtained for classes of the on time and off time distributions relevant to experimental situation. Analytical asymptotic scaling behaviors of the intensity correlation in the double time t and t' domain are obtained. In the scaling limit I(t)I(t+t('))-->h(x), where four classes of behaviors are found: (i) finite averaged on and off times x=t' (standard behavior); (ii) on and off times with identical power law behaviors x=t/t' (case relevant for capped nanocrystals); (iii) exponential on times and power law off times x=tt' (case relevant for uncapped nanocrystals); (iv) for defected off time distribution we also find x=t+t'. Origin of aging behavior is explained based on simple diffusion model. We argue that the diffusion controlled reaction A+B <==>AB, when followed on a single particle level exhibits aging behavior.

Fiber-type composition and fiber size of the human cricopharyngeal muscle and the pharyngeal constrictor muscle.

BACKGROUND: Despite a similar density of nicotinic acetylcholine receptors, the upper esophageal sphincter is sensitive to partial neuromuscular block, whereas the pharyngeal constrictor muscle is more resistant. In order to postulate possible mechanisms behind this difference in pharmacological response, basic knowledge of morphological and physiological features of these muscles is needed. The aim of this study was to compare the muscle fiber-type composition, the size and the morphology of the muscle fibers of the cricopharyngeal muscle, the main component of the upper esophageal sphincter, with that of the pharyngeal constrictor muscle. METHODS: Muscle specimens were obtained from five patients undergoing surgery with laryngectomy. Muscle fiber type was determined by myosin heavy chain immunohistochemistry and the muscle fiber cross-sectional area was measured for each fiber type by planimetry. Morphology of muscle fibers was evaluated by histochemistry. RESULTS: The muscle fiber cross-sectional area was generally smaller in the cricopharyngeal muscle compared with the pharyngeal constrictor muscle (P < 0.001). The composition of fiber types showed a large interindividual variability with no distinct difference between the studied muscles. Aberrant histological features were common in both the cricopharyngeal muscle and the pharyngeal constrictor muscle. CONCLUSION: The main morphological difference between the neuromuscular blocking agents sensitive cricopharyngeal muscle and the more resistant pharyngeal constrictor muscle is a uniformly smaller size of contributing fiber types in the cricopharyngeal muscle than in the pharyngeal constrictor muscle. The muscle fiber-type composition does not differ between the two studied muscles.

Acetylcholine receptor density in human cricopharyngeal muscle and pharyngeal constrictor muscle.

BACKGROUND: Upper esophageal sphincter resting tone is reduced during partial neuromuscular block, whereas contraction of the pharyngeal constrictor muscle is only slightly affected. We hypothesized that this difference may arise from differential nicotinic acetylcholine receptor (nAChR) density, the density supposedly being lower in the more sensitive cricopharyngeal muscle than in the resistant pharyngeal constrictor muscle. The aim of this study was to determine the density of nAChR in the main component of the upper esophageal sphincter, the cricopharyngeal muscle, and in the pharyngeal constrictor muscle. METHOD: After approval by the institutional ethics committee and informed consent, muscle specimens were obtained from five patients undergoing surgery with laryngectomy for malignancies of the larynx or thyroid gland. None had received radiation therapy to the affected area. The nAChR from these tissue specimens were solubilized and incubated with 125I-alpha-bungarotoxin. The quantity of radioligand-receptor complex was measured by radioactive decay in a liquid scintillation counter. The receptor density was expressed as femtomoles per milligram of protein (fmol/mg protein). RESULTS: The nAChR density was determined to 6.8 (3.5) fmol/mg protein (mean (SD)) in the cricopharyngeal muscle and 5.6 (2.1) fmol/mg protein in the pharyngeal constrictor muscle (P = 0.22). Although we could not find any difference in mean nAChR density, contrary to our hypothesis, the density in four of the five patients was higher in the cricopharyngeal muscle than in the pharyngeal constrictor muscle. CONCLUSION: Our results indicate that the density of nicotinic acetylcholine receptors is similar in the cricopharyngeal muscle and in the pharyngeal constrictor muscle. Nicotinic acetylcholine receptor density, as determined by 125I-alpha-bungarotoxin assay, cannot explain the difference in response to neuromuscular blocking drugs between the investigated muscles.

Parents' hostility in dyadic marital and triadic family settings and children's behavior problems.

The authors examined the relation between parents' hostility during conflict-focused discussions and child behavior problems. Parents engaged in 3 discussions: a dyadic marital discussion of marital disagreements, a dyadic marital discussion of child-related disagreements, and a triadic family discussion with the child about the child-related disagreements. Eighty-nine 2-parent community families with a child aged 9-13 years participated. A significant 3-way interaction between interparental hostility, parent-to-child hostility, and child sex accounted for variance in children's behavior problems. Among boys, higher levels of parent-to-child hostility during family discussions exacerbated the effects of interparental hostility on boys' adjustment. Thus, exposure to higher levels of both interparental and parent-to-child hostility may put boys at risk for developing internalizing and externalizing behavior problems.

Localization of sentinel nodes in head and neck tumours by combined lymphoscintigraphy and bone scintigraphy.

Sentinel node scintigraphy in tumours of the head and neck region was combined with bone scintigraphy to provide anatomical landmarks in order to better locate the lymph node uptake. 99Tc(m)-nanocolloid (40 MBq) was injected in the peritumour region 1 h after the administration of bone-seeking 99Tc(m)-methylene diphosphonate (200 MBq). After 5 min, A-P and lateral projections of the head and neck region were acquired. In all the 26 patients examined, the surrounding anatomy was clearly depicted. In 23 patients, the lymphatic drainage was identified within 30 min. In these patients, all hot spots appearing outside the deposited activity could be located according to the neck region classification system of the Memorial Sloan-Kettering Hospital. No lymphatic drainage was visualized in the remaining three patients. The injection of bone-seeking activity 1 h before deposition of the radiocolloid provided images visualizing soft tissues as well as skeletal structures, thus improving the topical diagnosis. Correlation with the results of surgery was not performed. The administration of a small amount of bone-seeking activity prior to sentinel node scintigraphy of head and neck tumours improves the anatomical localization of the lymph node activity.

Application of continuous time random walk theory to tracer test measurements in fractured and heterogeneous porous media.

We examine a set of analytical solutions based on the continuous time random walk (CTRW) approach, which can be evaluated numerically and used to analyze breakthrough data from tracer tests. Practical application of these solutions, with discussion of the physical meaning of the relevant model parameters, is emphasized. The CTRW theory accounts for the often observed non-Fickian (or scale-dependent) dispersion behavior that cannot be properly quantified by using the advection-dispersion equation. The solutions given here, valid for a wide range of dispersive behaviors of conservative tracers, and useful for both characterization and prediction, have been integrated into a library of external functions for use with the GRACE graphical display and analysis package. Example applications of these solutions are presented. The library and graphics software are freely accessible from a Web site.

Coparenting: a link between marital conflict and parenting in two-parent families.

Coparenting is examined as an explanatory link between marital conflict and parent-child relations in 2-parent families. Data were collected from 3 samples (pilot sample, n = 220 mothers; preadolescent sample, n = 75 couples; preschool sample, n = 172 couples) by using the Coparenting Questionnaire (G. Margolin, 1992b) to assess parents' perceptions of one another on 3 dimensions--cooperation, triangulation, and conflict. Main effects for child's age and for parents' gender were found for cooperation, and an interaction between parent and child gender was found for triangulation. Regression analyses were consistent with a model of coparenting mediating the relationship between marital conflict and parenting. Discussion addresses the theoretical and clinical importance of viewing coparenting as conceptually separate from other family processes.

Startle reactivity and PTSD symptoms in a community sample of women.

Exaggerated startle and PTSD symptoms have been investigated primarily in relation to acute or Type I stressors. The present study examined PTSD symptoms and startle eyeblink response in relation to chronic or Type II stressors. Type II stressors were operationally defined as high levels of childhood corporal punishment and high levels of current partner aggression. This study recruited a sample of 52 women from a metropolitan community and administered several questionnaires assessing experience of corporal punishment in childhood, current intimate partner aggression and level of PTSD symptoms. Following questionnaires, women were presented with eight auditory startle probes (white noise). Results showed that both childhood corporal punishment and intimate partner aggression were associated with women's PTSD symptom scores. However, only PTSD symptom scores were associated with reduced startle. Results are discussed in light of Type I and Type II stressors, and recent suggestions in the PTSD literature that a subgroup of individuals may experience physiological suppression rather than heightened physiological reactivity.

Leakage around voice prosthesis in laryngectomees: treatment with local GM-CSF.

OBJECTIVES: The aim of this study was to investigate the possibility of treating leakage around voice prosthesis by local injection of granulocyte-macrophage colony-stimulating factor (GM-CSF). STUDY DESIGN: Three patients with nonhealing leaking tracheoesophageal (TE) fistula, resistant to common treatment, were treated with local GM-CSF. MATERIAL AND METHODS: Fistula size was measured and photo documented before and after treatment. RESULT: In all three patients, the fistula shrank, and the leakage ceased. No side effects were observed. CONCLUSION: Local injection with GM-CSF seems to be a simple and effective way of decreasing a leaking TE-fistula in laryngectomized patients. A great advantage was that the procedure could be done with the voice prosthesis in place.

The effects of family and community violence on children.

This review examines theoretical and empirical literature on children's reactions to three types of violence--child maltreatment, community violence, and interparental violence. In addition to describing internalizing and externalizing problems associated with exposure to violence, this review identifies ways that violence can disrupt typical developmental trajectories through psychobiological effects, post-traumatic stress disorder (PTSD), cognitive consequences, and peer problems. Methodological challenges in this literature include high rates of co-occurrence among types of violence exposure, co-occurrence of violence with other serious life adversities, heterogeneity in the frequency, severity, age of onset, and chronicity of exposure, and difficulties in making causal inferences. A developmental psychopathology perspective focuses attention on how violence may have different effects at different ages and may compromise children's abilities to face normal developmental challenges. Emphasis is placed on the variability of children's reactions to violence, on outcomes that go beyond diagnosable disorders, and on variables that mediate and moderate children's reactions to violence.

The relationship between aggression in children and locus of control beliefs.

Gender differences are evident in the etiology and maintenance of aggressive behavior (which is on the increase for both male and female youths), but the explanatory models that have been proposed, including social learning theory and information processing models, are more appropriate for boys than for girls. In an attempt to elucidate processes underlying aggression, particularly for girls, the authors explored locus of control as a cognitive variable possibly related to aggressive behavior. The relationships between teacher-reported aggression and 3 types of locus of control (internal, powerful other, and unknown) for success and failure experiences were investigated. For girls, aggressive behavior was positively related to internal and unknown locus of control. In contrast, boys' aggressive behavior was unrelated to internal locus of control beliefs and negatively related to external locus of control beliefs. Possible explanatory mechanisms for the relationship between locus of control beliefs and aggression are discussed. The present study contributes to the understanding of aggression in girls and points to different processes underlying girls' and boys' aggression.

Observed sibling interaction: links with the marital and the mother-child relationship.

The study examines whether the link between the marital relationship and sibling interaction is direct or mediated by the mother-child relationship. Seventy-three same-sex siblings pairs aged 3 years 6 months to 8 years 6 months were observed during free play. Mothers completed questionnaires assessing marital functioning and their relationship with their 2 children. Results indicated that older siblings' negative behavior is linked with negative dimensions of the marital and the mother-child relationship, whereas younger siblings' negative behavior is linked with the mother-child and the differential mother-child relationship. Siblings; positive behavior, although linked with spacing, is not linked with positive dimensions of family interaction. Most important, the linkage between negative marital relations and older siblings; negative behavior was found to be mediated by maternal power assertion, thereby supporting the indirect model of negative family interaction.

The nuts and bolts of behavioral observation of marital and family interaction.

Despite considerable discussion in the literature about the advantages of observational research and the relative benefits of different coding systems and strategies, little is written about the actual implementation of this assessment strategy. This paper presents an overall framework as well as the essential components involved in collecting (selection of task, setting, unit of analysis, and coding system) and coding (transcribing, selecting and training coders, transforming data, and analyzing reliability) of observational data. To achieve success with observational methods, we emphasize several issues, including (a) the research question as the motivator for all decisions, (b) the interrelatedness of tasks, and (c) the implications of decisions early in the process for later stages of analysis and interpretation. Investigators are encouraged to communicate the details of their observational and coding procedures so that these methods are readily accessible for purposes of replication and comparison.

Mothers' and fathers' reports of children's reactions to naturalistic marital conflict.

OBJECTIVE: To examine how children, aged 8 to 11 years, react to observing their parents' naturally occurring marital conflict in their own homes and to compare reactions among children raised in homes characterized by different types of marital conflict. METHOD: For 5 1/2 weeks, mothers and fathers of 110 children used daily home diaries to record independently their children's reactions to marital conflict. Logistic regression compared the likelihood of exhibiting specific reactions to conflict among children from marriages characterized by low conflict (LOWCON; n = 37), nonphysical conflict (NOPHYCON; n = 35), and physical conflict (PHYCON; n = 38). RESULTS: Mothers' and fathers' reports indicate that children from PHYCON homes were more likely than children from LOWCON and NOPHYCON homes to leave the room, misbehave or appear angry, and appear sad or frightened. CONCLUSIONS: These results support the notion that different histories of exposure to marital conflict may contribute to the way in which children react to their parents' marital conflict.

Reliability and diagnostic efficacy of parents' reports regarding children's exposure to marital aggression.

Mothers, fathers, and 8- to 11-year-old children from 181 two-parent families independently reported on the occurrence of husband-to-wife physical aggression and wife-to-husband physical aggression; parents additionally indicated whether the child had been witness to the aggression. First this study examined interspousal agreement regarding whether parents have been physically aggressive toward one another and whether the child has witnessed interparental physical aggression. There was moderate agreement between parents as to the occurrence of physical aggression and only fair agreement as to whether the child saw or heard the aggression. Second, this study explored the diagnosticity of a joint parent report as an indicator of child exposure to marital aggression. Receiver operating characteristic (ROC) curves are presented separately for husbands' and wives' aggression, indicating the explicit trade-off between true positives (sensitivity) and false positives (one minus specificity) in using the joint parent report as a diagnostic indicator. Standard ROC analysis suggests that the joint parent report is equally diagnostic in predicting children's reports of exposure to husbands' and wives' aggression. Finally, decisions regarding how to use parent reports as an indicator of children's exposure to marital aggression are discussed as depending on the base rate of child reports of exposure and the objective sought in classifying children and/or families.