Multicomponent dynamical systems: SRB measures and phase transitions

We discuss a notion of phase transitions in multicomponent systems and clarify relations between deterministic chaotic and stochastic models of this type of systems. Connections between various definitions of SRB measures are considered as well.Comment: 13 pages, LaTeX 2

On local linearization of control systems

We consider the problem of topological linearization of smooth (C infinity or real analytic) control systems, i.e. of their local equivalence to a linear controllable system via point-wise transformations on the state and the control (static feedback transformations) that are topological but not necessarily differentiable. We prove that local topological linearization implies local smooth linearization, at generic points. At arbitrary points, it implies local conjugation to a linear system via a homeomorphism that induces a smooth diffeomorphism on the state variables, and, except at "strongly" singular points, this homeomorphism can be chosen to be a smooth mapping (the inverse map needs not be smooth). Deciding whether the same is true at "strongly" singular points is tantamount to solve an intriguing open question in differential topology

On the Lebesgue measure of Li-Yorke pairs for interval maps

We investigate the prevalence of Li-Yorke pairs for $C^2$ and $C^3$ multimodal maps $f$ with non-flat critical points. We show that every measurable scrambled set has zero Lebesgue measure and that all strongly wandering sets have zero Lebesgue measure, as does the set of pairs of asymptotic (but not asymptotically periodic) points. If $f$ is topologically mixing and has no Cantor attractor, then typical (w.r.t. two-dimensional Lebesgue measure) pairs are Li-Yorke; if additionally $f$ admits an absolutely continuous invariant probability measure (acip), then typical pairs have a dense orbit for $f \times f$. These results make use of so-called nice neighborhoods of the critical set of general multimodal maps, and hence uniformly expanding Markov induced maps, the existence of either is proved in this paper as well. For the setting where $f$ has a Cantor attractor, we present a trichotomy explaining when the set of Li-Yorke pairs and distal pairs have positive two-dimensional Lebesgue measure.Comment: 41 pages, 3 figure

Neuropsychological intervention in kindergarten children with subtyped risks of reading retardation

Kindergarten children at risk of developing language problems were administered the Florida Kindergarten Screening Battery. A principal components analysis revealed a verbal and a visual-spatial component and subsequent discriminant function analyses a high verbal/low visual-spatial group (LAL: Latent L) and a high visual-spatial/low verbal group (LAP: Latent P). LAL- and LAP-children were considered at risk for developing an L- or P-type of dyslexia, respectively. As is common practice with children suffering from manifest L- or Pdyslexia, the LAL- and LAP-kindergartners received right and left hemisphere stimulation, respectively. The outcomes were compared with those of bilateral hemispheric stimulation and no intervention. Reading tests were administered in primary school Grades 1 and 5/6; teachers' evaluation of reading took place in Grade 5/6. Overall, the LAL- and LAP- groups showed significant backwardness in word and text reading, both at early and late primary school. Types of intervention made a difference though: not significantly backward in early word, late word, and late text reading were the LAL-children who had received right hemisphere stimulation. Nonintervened LAP-children did not show significant backwardness in early word reading and late text reading, nor did LAP-children who had received left hemisphere or bilateral stimulation. Early text reading was not affected by any treatment. Teacher's evaluations were in support of these findings. Copyright © 2005 by The International Dyslexia Association®

Appetitive Traits associated with Higher and Lower Body Mass Index: Evaluating the Validity of the Adult Eating Behaviour Questionnaire in an Australian Sample

Background: The aims of this study were to evaluate the factor structure of the newly developed Adult Eating Behaviour Questionnaire (AEBQ) (Hunot et al., Appetite 105:356-63, 2016) in an Australian sample, and examine associations between the four food approach and four food avoidance appetitive traits with body mass index (BMI). Methods: Participants (N = 998) recruited between May and October 2016 via a university research participation scheme and online social network sites completed an online version of the AEBQ and self-reported demographic and anthropometric data. Of the sample, 84.8% were females, 29.6% had completed a university degree and the overall mean age was 24.32 years (SD = 8.32). Confirmatory factor analysis (CFA) was used to test three alternative factor structures (derived from issues raised in the original development study): the original 8 factor model, a 7 factor model with Food Responsiveness and Hunger scales combined, and a 7 factor model with the Hunger scale removed. Results: The CFA revealed that the original 8 factor model was a better fit to the data than the 7 factor model in which Food Responsiveness and Hunger scales were combined. However, while reliability estimates for 7 of the 8 scales were good (Cronbach’s α between 0.70-0.86), the reliability of the Hunger scale was modest (0.67) and dropping this factor resulted in a good fitting model. All food avoidance scales (except Food Fussiness) were negatively associated with body mass index (BMI) whereas Emotional Overeating was the only food approach scale positively associated with BMI. Conclusions: The study supports the use of the AEBQ as a reliable and valid measure of food approach and avoidance appetitive traits in adults. Longitudinal studies that examine continuity and stability of appetitive traits across the lifespan will be facilitated by the addition of this measurement tool to the literature

Factors associated with dropout from treatment for eating disorders: a comprehensive literature review

<p>Abstract</p> <p>Background</p> <p>Dropout (DO) is common in the treatment of eating disorders (EDs), but the reasons for this phenomenon remain unclear. This study is an extensive review of the literature regarding DO predictors in EDs.</p> <p>Methods</p> <p>All papers in PubMed, PsycINFO and Cochrane Library (1980-2009) were considered. Methodological issues and detailed results were analysed for each paper. After selection according to inclusion criteria, 26 studies were reviewed.</p> <p>Results</p> <p>The dropout rates ranged from 20.2% to 51% (inpatient) and from 29% to 73% (outpatient). Predictors of dropout were inconsistent due to methodological flaws and limited sample sizes. There is no evidence that baseline ED clinical severity, psychiatric comorbidity or treatment issues affect dropout. The most consistent predictor is the binge-purging subtype of anorexia nervosa. Good evidence exists that two psychological traits (high maturity fear and impulsivity) and two personality dimensions (low self-directedness, low cooperativeness) are related to dropout.</p> <p>Conclusion</p> <p>Implications for clinical practice and areas for further research are discussed. Particularly, these results highlight the need for a shared definition of dropout in the treatment of eating disorders for both inpatient and outpatient settings. Moreover, the assessment of personality dimensions (impulse control, self-efficacy, maturity fear and others) as liability factors for dropout seems an important issue for creating specific strategies to reduce the dropout phenomenon in eating disorders.</p

Early structural and functional defects in synapses and myelinated axons in stratum lacunosum moleculare in two preclinical models for tauopaty

The stratum lacunosum moleculare (SLM) is the connection hub between entorhinal cortex and hippocampus, two brain regions that are most vulnerable in Alzheimer’s disease. We recently identified a specific synaptic deficit of Nectin-3 in transgenic models for tauopathy. Here we defined cognitive impairment and electrophysiological problems in the SLM of Tau.P301L mice, which corroborated the structural defects in synapses and dendritic spines. Reduced diffusion of DiI from the ERC to the hippocampus indicated defective myelinated axonal pathways. Ultrastructurally, myelinated axons in the temporoammonic pathway (TA) that connects ERC to CA1 were damaged in Tau.P301L mice at young age. Unexpectedly, the myelin defects were even more severe in bigenic biGT mice that co-express GSK3β with Tau.P301L in neurons. Combined, our data demonstrate that neuronal expression of protein Tau profoundly affected the functional and structural organization of the entorhinal-hippocampal complex, in particular synapses and myelinated axons in the SLM. White matter pathology deserves further attention in patients suffering from tauopathy and Alzheimer’s disease

Common etiological architecture underlying reward responsiveness, externally driven eating behaviors, and BMI in childhood: findings from the Gemini twin cohort

BACKGROUND: Studies have reported that impulsivity predicts childhood BMI and that the association is mediated by eating behaviors. One aspect of impulsivity-potentially crucial in the obesity context-is reward responsiveness, which may predispose to responsiveness to palatable food cues. The behavioral susceptibility theory hypothesizes that genetic susceptibility to obesity operates partly via genetically determined differences in appetite regulation. Reward responsiveness may therefore be one of the neuro-endophenotypes that mediates genetic susceptibility to obesity. OBJECTIVE: To test whether reward responsiveness, eating behaviors, and child BMI share common genetic architecture. METHODS: We examined reward responsiveness, eating behaviors, and BMI in 5-year-old children from Gemini, a UK birth cohort of 2402 twin pairs born in 2007. All measures were collected by parent report. Reward responsiveness was derived from the Behavioral Approach System. Compulsion to eat and eating for pleasure was measured with the "food responsiveness" scale of the Child Eating Behavior Questionnaire. Wanting to eat in response to environmental food cues was measured with the "external eating" scale of the Dutch Eating Behavior Questionnaire. Maximum-likelihood structural equation modeling was used to establish underlying common genetic and environmental influences. RESULTS: There were significant positive phenotypic correlations between all traits except for reward responsiveness and BMI. Genetic factors explained the majority of the association between food responsiveness and external eating (74%, 95% CI: 61, 87), whereas common shared environmental factors explained the majority of the associations between reward responsiveness with both food responsiveness (55%, 95% CI: 20, 90) and external eating (70%, 95% CI: 39, 100). CONCLUSIONS: Our study demonstrates the importance of common environmental factors in the shared etiology between reward responsiveness and childhood eating behaviors. However, the common etiology underlying both reward responsiveness and BMI is unclear, as there was no phenotypic correlation between reward responsiveness and BMI at this age. Further longitudinal research needs to detangle this complex relationship throughout development

Hippocampal - diencephalic - cingulate networks for memory and emotion: An anatomical guide

This review brings together current knowledge from tract tracing studies to update and reconsider those limbic connections initially highlighted by Papez for their presumed role in emotion. These connections link hippocampal and parahippocampal regions with the mammillary bodies, the anterior thalamic nuclei, and the cingulate gyrus, all structures now strongly implicated in memory functions. An additional goal of this review is to describe the routes taken by the various connections within this network. The original descriptions of these limbic connections saw their interconnecting pathways forming a serial circuit that began and finished in the hippocampal formation. It is now clear that with the exception of the mammillary bodies, these various sites are multiply interconnected with each other, including many reciprocal connections. In addition, these same connections are topographically organised, creating further subsystems. This complex pattern of connectivity helps explain the difficulty of interpreting the functional outcome of damage to any individual site within the network. For these same reasons, Papez’s initial concept of a loop beginning and ending in the hippocampal formation needs to be seen as a much more complex system of hippocampal–diencephalic–cingulate connections. The functions of these multiple interactions might be better viewed as principally providing efferent information from the posterior medial temporal lobe. Both a subcortical diencephalic route (via the fornix) and a cortical cingulate route (via retrosplenial cortex) can be distinguished. These routes provide indirect pathways for hippocampal interactions with prefrontal cortex, with the preponderance of both sets of connections arising from the more posterior hippocampal regions. These multi-stage connections complement the direct hippocampal projections to prefrontal cortex, which principally arise from the anterior hippocampus, thereby creating longitudinal functional differences along the anterior–posterior plane of the hippocampus