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Variety Of Aspects (variety + of_aspect)

Distribution by Scientific Domains

Medical Sciences	40%

Selected Abstracts

Executive functions in children with dyslexia

DYSLEXIA, Issue 2 2005
Astrid Reiter
Abstract There is little data available concerning the executive functions of children with dyslexia. The small number of existing studies in this field focus on single aspects of these functions such as working memory. The aim of the present study was therefore to assess a variety of aspects of executive functioning in children with dyslexia. Forty-two children with dyslexia and 42 non-dyslexic children were examined using a neuropsychological test battery. The test battery consisted of standardised tests examining the assessment of working memory, concept formation, inhibition, flexibility, problem solving and fluency functions. Comparison between the test performance of non-dyslexic children and children with dyslexia revealed obvious difficulties of children with dyslexia in tests measuring working memory. Inhibition of inappropriate reactions was impaired in children with dyslexia in more demanding tests, but not in simple ones. Furthermore, children with dyslexia displayed impairments of both verbal and figural fluency functions. While in comparison to non-dyslexic children no disturbances of concept formation were observed, problem solving seemed to be partially impaired. The present findings suggest that children with dyslexia demonstrate impairments in a variety of executive functions. This should be considered in the development of new concepts in the treatment of dyslexia. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Lupus erythematosus: clinical and histopathological study of oral manifestations and immunohistochemical profile of epithelial maturation

JOURNAL OF CUTANEOUS PATHOLOGY, Issue 10 2006
Silvia Vanessa Lourenço
Background:, Lupus erythematosus (LE) is an autoimmune disease of unknown cause. Prevalence of oral involvement in patients with LE is uncertain but may vary from 9 to 45% in patients with systemic disease and from 3 to 20% in patients with chronic cutaneous involvement. Methods:, Incidence of oral lesions of LE and their clinical aspects were investigated. Their histopathologic features were analyzed, and the status of epithelial maturation was assessed through the expression patterns of cytokeratins. Results:, Twenty-six patients (from 188 examined) presented oral lesions of LE. Most of them were females (19) with systemic disease (11). Clinical aspects of these lesions varied, and lips and buccal mucosa were most affected. Histologically, lesions revealed lichenoid mucositis with perivascular infiltrate and thickening of basement. Cytokeratins profile showed hyperproliferative epithelium, with expression of CK5/6, and CK14 on all epithelial layers, CK16 on all suprabasal layers and CK10 on prickle cell layers only. Conclusions:, Oral lesions of LE show a variety of aspects, and their microscopic features are of a lichenoid mucositis with deep inflammatory infiltrate. Cytokeratins expression patterns are of hyperproliferative epithelium, and this phenomenon must be analyzed in relation to the inflammatory cytokines for a better understanding of the mechanisms of the disease. [source]

Understanding the role of tryptophan and serotonin metabolism in gastrointestinal function

NEUROGASTROENTEROLOGY & MOTILITY, Issue 12 2009
D. Keszthelyi
Abstract, Tryptophan is the precursor of a wide array of metabolites, which are involved in a variety of aspects of human nutrition and metabolism. Accumulating evidence suggests a role of tryptophan metabolites, especially serotonin (5-hydroxytryptamin) in intestinal (patho) physiology, although mechanisms of action are still poorly understood. Alterations of serotonin metabolism may give rise to gastrointestinal dysfunction. Recently, it has been postulated that other metabolites of tryptophan, mostly of the kynurenine pathway, also play a role in regulating gut function. This review analyses the current knowledge of the interrelationship between tryptophan metabolic pathways and summarizes the existing scientific evidence regarding the role of tryptophan metabolites in intestinal function and in the pathogenesis of gastrointestinal diseases. [source]

Epitaxial graphene: a new material

PHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 7 2008
Th. Seyller
Abstract Graphene, a two-dimensional sheet of sp2 -bonded carbon arranged in a honeycomb lattice, is not only the building block of fullerenes, carbon nano tubes (CNTs) and graphite, it also has interesting properties, which have caused a flood of activities in the past few years. The possibility to grow graphitic films with thicknesses down to a single graphene layer epitaxially on SiC{0001} surfaces is promising for future applications. The two-dimensional nature of epitaxial graphene films make them ideal objects for surface science techniques such as photoelectron spectroscopy, low-energy electron diffraction, and scanning probe microscopy. The present article summarizes results from recent photoemission studies covering a variety of aspects such as the growth of epitaxial graphene and few layer graphene, the electronic and structural properties of the interface to the SiC substrate, and the electronic structure of the epitaxial graphene stacks. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Individual versus social complexity, with particular reference to ant colonies

BIOLOGICAL REVIEWS, Issue 2 2001
CARL ANDERSON
ABSTRACT Insect societies , colonies of ants, bees, wasps and termites , vary enormously in their social complexity. Social complexity is a broadly used term that encompasses many individual and colony-level traits and characteristics such as colony size, polymorphism and foraging strategy. A number of earlier studies have considered the relationships among various correlates of social complexity in insect societies; in this review, we build upon those studies by proposing additional correlates and show how all correlates can be integrated in a common explanatory framework. The various correlates are divided among four broad categories (sections). Under ,polyphenism' we consider the differences among individuals, in particular focusing upon ,caste' and specialization of individuals. This is followed by a section on ,totipotency' in which we consider the autonomy and subjugation of individuals. Under this heading we consider various aspects such as intracolony conflict, worker reproductive potential and physiological or morphological restrictions which limit individuals' capacities to perform a range of tasks or functions. A section entitled ,organization of work' considers a variety of aspects, e.g. the ability to tackle group, team or partitioned tasks, foraging strategies and colony reliability and efficiency. A final section,,communication and functional integration', considers how individual activity is coordinated to produce an integrated and adaptive colony. Within each section we use illustrative examples drawn from the social insect literature (mostly from ants, for which there is the best data) to illustrate concepts or trends and make a number of predictions concerning how a particular trait is expected to correlate with other aspects of social complexity. Within each section we also expand the scope of the arguments to consider these relationships in a much broader sense of'sociality' by drawing parallels with other ,social' entities such as multicellular individuals, which can be understood as ,societies' of cells. The aim is to draw out any parallels and common causal relationships among the correlates. Two themes run through the study. The first is the role of colony size as an important factor affecting social complexity. The second is the complexity of individual workers in relation to the complexity of the colony. Consequently, this is an ideal opportunity to test a previously proposed hypothesis that ,individuals of highly social ant species are less complex than individuals from simple ant species' in light of numerous social correlates. Our findings support this hypothesis. In summary, we conclude that, in general, complex societies are characterized by large colony size, worker polymorphism, strong behavioural specialization and loss of totipotency in its workers, low individual complexity, decentralized colony control and high system redundancy, low individual competence, a high degree of worker cooperation when tackling tasks, group foraging strategies, high tempo, multi-chambered tailor-made nests, high functional integration, relatively greater use of cues and modulatory signals to coordinate individuals and heterogeneous patterns of worker-worker interaction. Key words: Ants, insect societies, individual complexity, social complexity, polyphenism, totitpotency, work organization, functional integration, sociality. [source]