Volatile Signals During Pregnancy: A Possible Chemical Basis for Mother–Infant Recognition

Human pheromones play a role in regulating relationships and apparently influence partner choice and mother–infant recognition. We analyzed the chemical content of volatiles from sweat patch samples from the para-axillary and nipple–areola regions of women during pregnancy and after childbirth. Solid phase microextraction was used to extract the volatile compounds, which were then characterized and quantified by gas chromatography–mass spectrometry. During pregnancy, women developed a distinctive pattern of five volatile compounds common to the para-axillary and nipple–areola regions (1-dodecanol, 1-1′-oxybis octane, isocurcumenol, α-hexyl-cinnamic aldehyde, and isopropyl myristate). These compounds were absent outside pregnancy and had slightly different patterns in samples from the two body areas. Differentiation of the volatile patterns among pregnant women may help newborns to distinguish their own mothers.     

Parameters identification of Van der Pol–Duffing oscillators via particle swarm optimization and differential evolution

Many of the proposed approaches for non-linear systems control are developed under the assumption that all involved parameters are known in advance. Unfortunately, their estimation is not so simple because the nature of the non-linear behaviors is very complex in the most part of the cases.In view of this complication, parameters identification of non-linear oscillators has attracted increasing interests in various research fields: from a pure mathematical point-of-view, parameters identification can be formalized as a multi-dimensional optimization problem, typically over real bounded domains. In doing this, the use of the so-called non-classical methods based on soft computing theories seems to be promising because they do not require a priori information and the robustness of the identification against the noise contamination is satisfactory. However, further studies are required to evaluate the general effectiveness of these methodologies. In this sense, the paper addresses the consistency of two classes of soft computing based methods for the identification of Van der Pol–Duffing oscillators. A large numerical investigation has been conducted to evaluate the performances of six differential evolution algorithms (including a modified differential evolution algorithm proposed by the authors) and four swarm intelligence based algorithms (including a chaotic particle swarm optimization algorithm). Single well, double well and double-hump oscillators are identified and noisy system responses are considered in order to evaluate the robustness of the identification processes. The investigated soft computing techniques behave very well and thus they are suitable for practical applications.     

Analysing Cognitive Behaviour using LOTOS and Mexitl

We argue that cognitive models should be used in analysing the usability of multi-modal human computer interfaces and further, that formal methods can be advantageously applied to such analysis. In pursuing this objective we specify the Interacting Cognitive Subsystems model formally using the process calculus LOTOS and then we verify that it satisfies certain behavioural goals formulated in the interval temporal logic Mexitl. Received September 1998 / Accepted in revised form July 1999     

On Origins of Time-Dependence in Contact Angle Measurements

Time-dependent variations have been observed in the contact angles of wetting fluids on surfaces of homopolymers poly(styrene) (PS) and poly(methyl methacrylate) (PMMA), and copolymers of styrene and 4-vinyl pyridine (P(S-4VP)) and styrene and methacrylic acid (P(S-MAA)). Variations in the case of PS were unimportant, but significant variations occurred with the other polymers, allowing for the definition of both initial and equilibrium contact angle values. The total change in contact angles was strongly dependent on the acid-base contribution to the free energy of adsorption of the wetting fluids on the respective polymer surfaces, as determined from inverse gas chromatography experiments. A tentative correlation also linked the total change in contact angle with the ability of the polymer surfaces to reorganize when in contact with the polar wetting fluids of this study. Careful consideration must be given to the possibility of polymer surface reorganization when selecting fluids for use in the collection of reliable contact angle data.     

Determinants of attrition from cessation treatment in smokers with a history of major depressive disorder.

Attrition from smoking cessation treatment by individuals with a history of major depression was investigated. An investigation of preinclusion attrition examined differences between 258 eligible smokers who did and 100 who did not attend an initial assessment session. Postinclusion attrition was investigated by comparing the 33 early dropouts, 27 late dropouts, and 117 treatment completers. Those who failed to attend the assessment session were more likely to be female, to smoke cigarettes with higher nicotine content, and to have a history of psychotropic medication use. Early-treatment dropouts reported a higher smoking rate than late-treatment dropouts and endorsed more symptoms of depression than late dropouts and treatment completers. Results are compared with previous investigations of smoking cessation attrition, and implications for treatment and attrition prevention are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Secrecy and group creation

We add an operation of group creation to the typed π-calculus, where a group is a type for channels. Creation of fresh groups has the effect of statically preventing certain communications, and can block the accidental or malicious leakage of secrets. Intuitively, no channel belonging to a fresh group can be received by processes outside the initial scope of the group, even if those processes are untyped. We formalize this intuition by adapting a notion of secrecy introduced by Abadi, and proving a preservation of secrecy property.     

Does Barbie make girls want to be thin? The effect of experimental exposure to images of dolls on the body image of 5- to 8-year-old girls.

[Correction Notice: An erratum for this article was reported in Vol 42(6) of Developmental Psychology (see record 2006-20488-033). A substantive error occurs in the Body shape dissatisfaction section on page 287. The sentence describing the calculation of body shape dissatisfaction scores from girls' responses to the Child Figure Rating Scale should instead read as follows: "A body shape dissatisfaction score was computed by subtracting the girl's actual from her ideal body size."] The ubiquitous Barbie doll was examined in the present study as a possible cause for young girls' body dissatisfaction. A total of 162 girls, from age 5 to age 8, were exposed to images of either Barbie dolls, Emme dolls (U.S. size 16), or no dolls (baseline control) and then completed assessments of body image. Girls exposed to Barbie reported lower body esteem and greater desire for a thinner body shape than girls in the other exposure conditions. However, this immediate negative impact of Barbie doll was no longer evident in the oldest girls. These findings imply that, even if dolls cease to function as aspirational role models for older girls, early exposure to dolls epitomizing an unrealistically thin body ideal may damage girls' body image, which would contribute to an increased risk of disordered eating and weight cycling. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How does optimism suppress immunity? Evaluation of three affective pathways.

Studies have linked optimism to poorer immunity during difficult stressors. In this study, when 1st-year law students (N = 46) relocated to attend law school, reducing conflict among curricular and extracurricular goals, optimism predicted larger delayed-type hypersensitivity responses, indicating more robust in vivo cellular immunity. However, when students did not relocate, increasing goal conflict, optimism predicted smaller responses. Although this effect has been attributed to negative affect when difficult stressors violate optimistic expectancies, distress did not mediate optimism's effects on immunity. Alternative affective mediators related to engagement--engaged affect and fatigue--likewise failed to mediate optimism's effects, although all 3 types of affect independently influenced in vivo immunity. Alternative pathways include effort or self-regulatory depletion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On Reachability and Spatial Reachability in Fragments of BioAmbients

BioAmbients is a powerful model for representing various aspects of living cells. The model provides a rich set of operations for the movement and interaction of molecules. The richness of the language motivates the study of dialects of the full model and the comparison with other computational models. In this paper we investigate the limit between decidability and undecidability of two decision problems, namely reachability and spatial reachability, for semantic and syntactic fragments of BioAmbients providing movement capabilities and merge. Our results illustrate the power of merge with respect to the other movement operations of BA for properties like reachability. Furthermore, they establish an interesting connection between BioAmbients and other computational models like associative-commutative term rewriting and Petri nets with transfer arcs.     

Asymmetries in Visual-Spatial Processing Following Childhood Stroke.

The authors compared hemisphere-based and cognitive-domain-based hypotheses for visual-spatial deficits in children with stroke (n = 33) and children without stroke (n = 43). Children with unilateral left (n = 14) or right (n = 7) injury showed less efficient search for the visual field contralateral to their injury. Right-hemisphere injury was associated with deficient global-level processing and coordinate spatial judgments. Left-hemisphere injury resulted in relatively intact local versus global processing and categorical versus coordinate judgments. Bilateral injury (n = 12) resulted in disruption of visual search across visual fields and relative deficits in global-level processing and coordinate spatial judgments. Recovery of visual-spatial processing in children following childhood stroke is task specific. Certain visual-spatial functions typically mediated by the left hemisphere appear less vulnerable to disruption. (PsycINFO Database Record (c) 2010 APA, all rights reserved)