Heavy metal bioaccumulation and biomarkers of oxidative stress in the wild African tiger frog, Hoplobatrachus occipitalis

Human activities can have dramatic effects on animal populations around urban areas with heavy metal contamination being a primary cause of harm. Amphibians, as residents of aquatic systems and with their semi-permeable skin are especially susceptible to heavy metal contamination. To better understand the effect of heavy metals on Wild African Tiger frogs (Hoplobatrachus occipitalis) and the resulting production of oxidative stress enzymes, the concentrations of the heavy metals, cadmium (Cd), copper (Cu), iron (Fe), zinc (Zn), lead (Pb) and nickel (Ni) were investigated in the tissues of H. occipitalis as well as in water and sediment samples collected from five different locations in Lagos State, Nigeria. The activities of superoxide dismutase (SOD), reduced glutathione (GSH) and level of lipid peroxidation product, malondialdehyde (MDA) were analyzed in the liver of the sampled frogs. Most measured physicochemical characteristics of the water varied significantly across the sampling locations (P<0.05). The levels of metals (mg/kg dry weight) in muscle tissues also varied significantly across the locations (P<0.05) and ranged as follows: Cd: 0.21-5.03, Cu: 0.74-13.40, Fe: 3.19-109.10, Zn: 3.70-120.20, Pb: 0.12-18.24 and Ni: 3.20-7.28. Zn was the most accumulated metal, followed by Fe, Cu and Ni, while Pb was the least. The mean of SOD and reduced GSH in the frogs indicate some responses to oxidative stress which varied significantly among sampling areas (P<0.05). MDA values however did not consistently correlate with either oxidative stress or heavy metal concentrations in the frogs. The water-sediment-tissue analysis for heavy metals demonstrated that the sediment concentrated more heavy metals than water, while the frog tissues accumulated these metals articularly in more polluted areas.Key words: Heavy metal pollution, bioaccumulation, Hoplobatrachus occipitalis, biomarkers, oxidative stress

HTR4 gene structure and altered expression in the developing lung

Background: Meta-analyses of genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) spanning the 5-hydroxytryptamine receptor 4 (5-HT4R) gene (HTR4) associated with lung function. The aims of this study were to i) investigate the expression profile of HTR4 in adult and fetal lung tissue and cultured airway cells, ii) further define HTR4 gene structure and iii) explore the potential functional implications of key SNPs using a bioinformatic approach

Further evidence for the planet around 51 Pegasi

The discovery of the planet around the solar-type star 51 Pegasi marked a watershed in the search for extrasolar planets. Since then seven other solar-type stars have been discovered, of which several have surprisingly short orbital periods, like the planet around 51 Peg. These planets were detected using the indirect technique of measuring variations in the Doppler shifts of lines in the spectra of the primary stars. But it is possible that oscillations of the stars themselves (or other effects) could mimic the signature of the planets, particularly around the short-period planets. The apparent lack of spectral and brightness variations, however, led to widespread acceptance that there is a planet around 51 Peg. This conclusion was challenged by the observation of systematic variations in the line profile shapes of 51 Peg, which suggested stellar oscillations. If these observations are correct, then there is no need to invoke a planet around 51 Peg to explain the data. Here we report observations of 51 Peg at a much higher spectral resolution than those in ref.9, in which we find no evidence for systematic changes in the line shapes. The data are most consistent with a planetary companion to 51 Peg.Comment: LaTeX, 6 pages, 2 figures. To appear in 8 January 1998 issue of Natur

Verbal and non-verbal fluency in adults with developmental dyslexia: Phonological processing or executive control problems?

The executive function of fluency describes the ability to generate items according to specific rules. Production of words beginning with a certain letter (phonemic fluency) is impaired in dyslexia, whilst generation of words belonging to a certain semantic category (semantic fluency) is typically unimpaired. However, in dyslexia, verbal fluency has generally been studied only in terms of overall words produced. Furthermore, performance of adults with dyslexia on non-verbal design fluency tasks has not been explored but would indicate whether deficits could be explained by executive control, rather than phonological processing, difficulties. Phonemic, semantic, and design fluency tasks were presented to adults with dyslexia and without dyslexia, using fine-grained performance measures and controlling for IQ. Hierarchical regressions indicated that dyslexia predicted lower phonemic fluency, but not semantic or design fluency. At the fine-grained level, dyslexia predicted a smaller number of switches between subcategories on phonemic fluency, whilst dyslexia did not predict the size of phonemically-related clusters of items. Overall, the results suggested that phonological processing problems were at the root of dyslexia-related fluency deficits; however, executive control difficulties could not be completely ruled out as an alternative explanation. Developments in research methodology, equating executive demands across fluency tasks, may resolve this issue

Arquitetura da informação pervasiva

Este livro é indicado não apenas para estudantes, profissionais e pesquisadores que trabalhem com Ciência da Informação e Arquitetura da Informação, mas também para todos que militem em áreas como a ciência da computação, comunicação, arquitetura, design gráfico e outras. Os autores, primeiramente, contextualizam as dinâmicas sociotecnológicas pertinentes ao mundo contemporâneo; posteriormente, apresentam a Arquitetura da Informação sob diversos aspectos – discutindo o tema por um viés epistêmico – e discutem a Arquitetura da Informação sob quatro diferentes abordagens – arquitetural, sistêmica, informacional e pervasiva. Por fim, analisam o tema que é objeto central da obra: a Arquitetura da informação pervasiva

Inhalation of the Rho-kinase inhibitor Y-27632 reverses allergen-induced airway hyperresponsiveness after the early and late asthmatic reaction

BACKGROUND: In guinea pigs, we have previously demonstrated that the contribution of Rho-kinase to airway responsiveness in vivo and ex vivo is enhanced after active sensitization with ovalbumin (OA). Using conscious, unrestrained OA-sensitized guina pigs, we now investigated the role of Rho-kinase in the development of airway hyperresponsiveness (AHR) after the allergen-induced early (EAR) and late asthmatic reaction (LAR) in vivo. METHODS: Histamine and PGF(2α )PC(100)-values (provocation concentrations causing 100% increase in pleural pressure) were assessed before OA-challenge (basal airway responsiveness) and after the OA-induced EAR (5 h after challenge) and LAR (23 h after challenge). Thirty minutes later, saline or the specific Rho-kinase inhibitor Y-27632 (5 mM, nebulizer concentration) were nebulized, after which PC(100)-values were reassessed. RESULTS: In contrast to saline, Y-27632 inhalation significantly decreased the basal responsiveness toward histamine and PGF(2α )before OA-challenge, as indicated by increased PC(100 )-values. Both after the allergen-induced EAR and LAR, AHR to histamine and PGF(2α )was present, which was reversed by Y-27632 inhalation. Moreover, there was an increased effectiveness of Y-27632 to reduce airway responsiveness to histamine and PGF(2α )after the EAR and LAR as compared to pre-challenge conditions. Saline inhalations did not affect histamine or PGF(2α )PC(100)-values at all. Interestingly, under all conditions Y-27632 was significantly more effective in reducing airway responsiveness to PGF(2α )as compared to histamine. Also, there was a clear tendency (P = 0.08) to a more pronounced degree of AHR after the EAR for PGF(2α )than for histamine. CONCLUSION: The results indicate that inhalation of the Rho-kinase inhibitor Y-27632 causes a considerable bronchoprotection to both histamine and PGF(2α). Moreover, the results are indicative of a differential involvement of Rho-kinase in the agonist-induced airway obstruction in vivo. Increased Rho-kinase activity contributes to the allergen-induced AHR to histamine and PGF(2α )after both the EAR and the LAR, which is effectively reversed by inhalation of Y-27632. Therefore, Rho-kinase can be considered as a potential pharmacotherapeutical target in allergic asthma

A Method for Serial Tissue Processing and Parallel Analysis of Aberrant Crypt Morphology, Mucin Depletion, and Beta-Catenin Staining in an Experimental Model of Colon Carcinogenesis

The use of architectural and morphological characteristics of cells for establishing prognostic indicators by which individual pathologies are assigned grade and stage is a well-accepted practice. Advances in automated micro- and macroscopic image acquisition and digital image analysis have created new opportunities in the field of prognostic assessment; but, one area in experimental pathology, animal models for colon cancer, has not taken advantage of these opportunities. This situation is primarily due to the methods available to evaluate the colon of the rodent for the presence of premalignant and malignant pathologies. We report a new method for the excision and processing of the entire colon of the rat and illustrate how this procedure permitted the quantitative assessment of aberrant crypt foci (ACF), a premalignant colon pathology, for characteristics consistent with progression to malignancy. ACF were detected by methylene blue staining and subjected to quantitative morphometric analysis. Colons were then restained with high iron diamine–alcian blue for assessment of mucin depletion using an image overlay to associate morphometric data with mucin depletion. The subsequent evaluation of ACF for beta-catenin staining is also demonstrated. The methods described are particularly relevant to the screening of compounds for cancer chemopreventive activity

A Self-Reference False Memory Effect in the DRM Paradigm: Evidence from Eastern and Western Samples

It is well established that processing information in relation to oneself (i.e., selfreferencing) leads to better memory for that information than processing that same information in relation to others (i.e., other-referencing). However, it is unknown whether self-referencing also leads to more false memories than other-referencing. In the current two experiments with European and East Asian samples, we presented participants the Deese-Roediger/McDermott (DRM) lists together with their own name or other people’s name (i.e., “Trump” in Experiment 1 and “Li Ming” in Experiment 2). We found consistent results across the two experiments; that is, in the self-reference condition, participants had higher true and false memory rates compared to those in the other-reference condition. Moreover, we found that selfreferencing did not exhibit superior mnemonic advantage in terms of net accuracy compared to other-referencing and neutral conditions. These findings are discussed in terms of theoretical frameworks such as spreading activation theories and the fuzzytrace theory. We propose that our results reflect the adaptive nature of memory in the sense that cognitive processes that increase mnemonic efficiency may also increase susceptibility to associative false memories