Effects of PVA sponge containing chitooligosaccharide in the early stage of wound healing

Poly(vinyl alcohol) (PVA) sponges with different chitooligosaccharide (COS) content were prepared for wound-dressing application. The morphological structure of PVA sponges was observed by scanning electron microscopy. As the concentration of COS-loaded PVA sponge increased, the average pore size of sponge decreased and the release rate of COS from the sponge also slightly decreased. The accelerating effect of the COS-loaded PVA sponges on open wound healing in rats was investigated by macroscopic examination and measurement of wound area. The COS-loaded sponges were found to be very effective as a wound-healing accelerator in the early stage of wound healing. The wound treated with the COS-loaded PVA sponge was almost reepithelialized, granulation tissues in the wound were considerably replaced by fibrosis at 8 days after initial wounding. The COS-loaded PVA sponge was considered to be a suitable wound-healing formulation due to its easy preparation and high effectiveness.     

Review of Handbook of functional neuroimaging of cognition.

Reviews the book, Handbook of functional neuroimaging of cognition by Roberto Cabeza and Alan Kingstone. In fairness to the contributors of this excellent volume, much of the contents deals with sober reflection on the difficulties and uncertainties of interpreting the neuroimaging data in a variety of domains such as attention, vision, semantic and episodic memory, language, and working memory. In general, the authors of this volume present a fair, sophisticated, and valuable overview of the progress (or lack thereof) that functional imaging has contributed in a variety of different domains. This book provides a sense of a field that is undergoing rapid development and that clearly will have much to offer in the future. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Semantic and visual determinants of face recognition in a prosopagnosic patient

Prosopagnosia is the neuropathological inability to recognize familiar people by their faces. It can occur in isolation or can coincide with recognition deficits for other nonface objects. Often, patients whose prosopagnosia is accompanied by object recognition difficulties have more trouble identifying certain categories of objects relative to others. In previous research, we demonstrated that objects that shared multiple visual features and were semantically close posed severe recognition difficulties for a patient with temporal lobe damage. We now demonstrate that this patient's face recognition is constrained by these same parameters. The prosopagnosic patient ELM had difficulties pairing faces to names when the faces shared visual features and the names were semantically related (e.g., Tonya Harding, Nancy Kerrigan, and Josee Chouinard -three ice skaters). He made tenfold fewer errors when the exact same faces were associated with semantically unrelated people (e.g., singer Celine Dion, actress Betty Grable, and First Lady Hillary Clinton). We conclude that prosopagnosia and co-occurring category-specific recognition problems both stem from difficulties disambiguating the stored representations of objects that share multiple visual features and refer to semantically close identities or concepts.     

Does face inversion change spatial frequency tuning?

The authors examined spatial frequency (SF) tuning of upright and inverted face identification using an SF variant of the Bubbles technique (F. Gosselin & P. G. Schyns, 2001). In Experiment 1, they validated the SF Bubbles technique in a plaid detection task. In Experiments 2a–c, the SFs used for identifying upright and inverted inner facial features were investigated. Although a clear inversion effect was present (mean accuracy was 24% higher and response times 455 ms shorter for upright faces), SF tunings were remarkably similar in both orientation conditions (mean r = .98; an SF band of 1.9 octaves centered at 9.8 cycles per face width for faces of about 6°). In Experiments 3a and b, the authors demonstrated that their technique is sensitive to both subtle bottom-up and top-down induced changes in SF tuning, suggesting that the null results of Experiments 2a–c are real. The most parsimonious explanation of the findings is provided by the quantitative account of the face inversion effect: The same information is used for identifying upright and inverted inner facial features, but processing has greater sensitivity with the former. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Testing a series of causal propositions relating time in child care to children’s externalizing behavior.

[Correction Notice: An erratum for this article was reported in Vol 46(2) of Developmental Psychology (see record 2010-03975-013). On the first page of the article “Testing a Series of Causal Propositions Relating Time in Child Care to Children’s Externalizing Behavior,” by Kathleen McCartney, Margaret Burchinal, Alison Clarke- Stewart, Kristen L. Bub, Margaret T. Owen, Jay Belsky, and the NICHD Early Child Care Research Network (Developmental Psychology, 2010, Vol. 46, No. 1, pp. 1–17), author Alison Clarke- Stewart’s name was misspelled as Aliso Clarke-Stewart. In addition, the e-mail address listed for the corresponding author Kathleen McCartney is incorrect. The correct e-mail address is: kathleen_mccartney@gse.harvard.edu. The online versions of this article have been corrected.] Prior research has documented associations between hours in child care and children’s externalizing behavior. A series of longitudinal analyses were conducted to address 5 propositions, each testing the hypothesis that child care hours causes externalizing behavior. Data from the National Institute of Child Health and Human Development Early Child Care Research Network (NICHD) Study of Early Child Care and Youth Development were used in this investigation because they include repeated measures of child care experiences, externalizing behavior, and family characteristics. There were 3 main findings. First, the evidence linking child care hours with externalizing behavior was equivocal in that results varied across model specifications. Second, the association between child care hours and externalizing behavior was not due to a child effect. Third, child care quality and proportion of time spent with a large group of peers moderated the effects of child care hours on externalizing behavior. The number of hours spent in child care was more strongly related to externalizing behavior when children were in low-quality child care and when children spent a greater proportion of time with a large group of peers. The magnitude of associations between child care hours and externalizing behavior was modest. Implications are that parents and policymakers must take into account that externalizing behavior is predicted from a constellation of variables in multiple contexts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The role of heterogeneities and intercellular coupling in wave propagation in cardiac tissue

Electrical heterogeneities play a role in the initiation of cardiac arrhythmias. In certain pathological conditions such as ischaemia, current sinks can develop in the diseased cardiac tissue. In this study, we investigate the effects of changing the amount of heterogeneity and intercellular coupling on wavefront stability in a cardiac cell culture system and a mathematical model of excitable media. In both systems, we observe three types of behaviour: plane wave propagation without breakup, plane wave breakup into spiral waves and plane wave block. In the theoretical model, we observe a linear decrease in propagation velocity as the number of heterogeneities is increased, followed by a rapid, nonlinear decrease to zero. The linear decrease results from the heterogeneities acting independently on the wavefront. A general scaling argument that considers the degree of system heterogeneity and the properties of the excitable medium is used to derive a dimensionless parameter that describes the interaction of the wavefront with the heterogeneities.     

Multiple steady states for isothermal catalytic gas—solid reactions with a positive reaction order

The multiplicity of steady states of solid catalysed gas reactions induced by multicomponent diffusion is described, and a necessary condition for existence is given. Two examples of such multiple steady states are discussed and their stability analyzed.