123 research outputs found
Confocal laser scanning microscopy (CLSM) study of hepatocytes cultured on collagen films and gels
Summary of paper describing the process whereby primary hepatocyte cultures form an integral part of many hybrid artificial liver designs, and the extracellular matrix environment of the cultures is an important factor for optimal expression of hepatocyte-specific phenotype. This study investigates the effect of incorporating 20% chondroitin-6-sulphate (Ch6SO4), a glycosaminoglycan (GAG), into collagen films and gels, and crosslinking the films and the gels with 1,6-diaminohexane (DAH) on the viability of hepatocytes cultured for 48 hours
Parental agency, identity and knowledge: mothers of children with dyslexia
This is a postprint of an article whose final and definitive form has been published in the Oxford Review of Education© 2004 Copyright Taylor & Francis; Oxford Review of Education is available online at http://www.informaworld.comIn this paper we report and analyse findings from part of a two-year evaluation project which focuses on parent-professional communications over the issues of learning difficulties arising from dyslexia. The key concepts in this study are dyslexia friendly schools and parental partnership, which are discussed in the current policy interest in inclusive education and parent partnership. A conceptual framework has been derived from the study which focuses on parental strategies to ensure adequate provision for their children, knowledge about dyslexia and identity, in particular that of the mother of the child with dyslexia. Excerpts from in-depth interviews of parents are then presented to illustrate the framework. The significance of the findings is examined in relation to other studies of parent partnership. Implications for a more inclusive version of extended professionalism are also considered
Yeasts and wine off-flavours: a technological perspective
Review article. Part of the special issue "Wine microbiology and safety: from the vineyard to the bottle (Microsafety Wine)", 19-20 Nov. 2009, ItalyIn wine production, yeasts have both beneficial
and detrimental activities. Saccharomyces cerevisiae is the
yeast mainly responsible for turning grape juice into wine
but this species and several others may also show
undesirable effects in wines. Among such effects, technologists
are particularly concerned with the production of offflavours
that may occur during all stages of winemaking.
Typical spoiling activities include the production of ethyl
acetate by apiculate yeasts before fermentation, hydrogen
sulphide by S. cerevisiae during fermentation phases,
acetaldehyde by film-forming yeasts during bulk storage,
and volatile phenols by Dekkera bruxellensis during storage
or after bottling. The occurrence of these hazards depends
on the technological operations designed to obtain a given
type of wine and most can be avoided by current preventive
or curative measures. On the contrary, good manufacturing
practices must be strengthened to deal with the problem of
volatile phenol production in red wines. Appropriate
monitoring of D. bruxellensis populations and quantification
of 4-ethylphenol is advised during storage, particularly
when oak barrels are used, and absence of viable cells must
be guaranteed in bottled wines. This work, which is based
on our experience at winery level, aims to provide
information on appropriate technological strategies to deal
with the problem of off-flavours produced by yeasts
Predicting Transitions in Low and High Levels of Risk Behavior from Early to Middle Adolescence: The TRAILS Study
The present study examined the joint development of substance use and externalizing problems in early and middle adolescence. First, it was tested whether the relevant groups found in previous studies i.e., those with an early onset, a late onset, and no onset or low levels of risk behavior could be identified, while using a developmental model of a single, underlying construct of risk behavior. Second, departing from Moffitt’s taxonomy of antisocial behavior, it was tested if early, but not late, onset risk behavior is predicted by a problematic risk profile in childhood. Data were used from TRAILS, a population based cohort study, starting at age 11 with two follow-ups at mean ages of 13.6 and 16.3 years. Latent transition analyses demonstrated that, both in early and middle adolescence, a single underlying construct of risk behavior, consisting of two classes (labeled as low and high risk behavior), adequately represented the data. Respondents could be clearly classified into four possible transition patterns from early to middle adolescence, with a transition from high to low being almost non-existent (2.5 %), low to low (39.4 %) and low to high (41.8 %) being the most prevalent, and high to high (16.2 %) substantial. As hypothesized, only the high-high group was characterized by a clear adverse predictor profile in late childhood, while the low-high group was not. This study demonstrates that the development of substance use is correlated with externalizing problems and underscores the theory that etiologies of early and later onset risk behavior are different
Does administration of non-steroidal anti-inflammatory drug determine morphological changes in adrenal cortex: ultrastructural studies
Rofecoxib (Vioxx© made by Merck Sharp & Dohme, the USA) is a non-steroidal anti-inflammatory drug which belongs to the group of selective inhibitors of cyclooxygenasis-2, i.e., coxibs. Rofecoxib was first registered in the USA, in May 1999. Since then the drug was received by millions of patients. Drugs of this group were expected to exhibit increased therapeutic action. Additionally, there were expectations concerning possibilities of their application, at least as auxiliary drugs, in neoplastic therpy due to intensifying of apoptosis. In connection with the withdrawal of Vioxx© (rofecoxib) from pharmaceutical market, attempts were made to conduct electron-microscopic evaluation of cortical part of the adrenal gland in preparations obtained from animals under influence of the drug. Every morning animals from the experimental group (15 rats) received rofecoxib (suspension in physiological saline)—non-steroidal anti-inflammatory drug (Vioxx©, Merck Sharp and Dohme, the USA), through an intragastric tube in the dose of 1.25 mg during 8 weeks. In the evaluated material, there was found a greater number of secretory vacuoles and large, containing cholesterol and other lipids as well as generated glucocorticoids, lipid drops in cytoplasm containing prominent endoplasmic reticulum. There were also found cells with cytoplasm of smaller density—especially in apical and basal parts of cells. Mitochondria occasionally demonstrated features of delicate swelling. The observed changes, which occurred on cellular level with application of large doses of the drug, result from mobilization of adaptation mechanisms of the organism
Diversity of Meiofauna from the 9°50′N East Pacific Rise across a Gradient of Hydrothermal Fluid Emissions
Background: We studied the meiofauna community at deep-sea hydrothermal vents along a gradient of vent fluid emissions in the axial summit trought (AST) of the East Pacific Rise 9 degrees 50'N region. The gradient ranged from extreme high temperatures, high sulfide concentrations, and low pH at sulfide chimneys to ambient deep-sea water conditions on bare basalt. We explore meiofauna diversity and abundance, and discuss its possible underlying ecological and evolutionary processes.
Methodology/Principal Findings: After sampling in five physico-chemically different habitats, the meiofauna was sorted, counted and classified. Abundances were low at all sites. A total of 52 species were identified at vent habitats. The vent community was dominated by hard substrate generalists that also lived on bare basalt at ambient deep-sea temperature in the axial summit trough (AST generalists). Some vent species were restricted to a specific vent habitat (vent specialists), but others occurred over a wide range of physico-chemical conditions (vent generalists). Additionally, 35 species were only found on cold bare basalt (basalt specialists). At vent sites, species richness and diversity clearly increased with decreasing influence of vent fluid emissions from extreme flow sulfide chimney (no fauna), high flow pompei worm (S: 4-7, H-loge': 0.11-0.45), vigorous flow tubeworm (S: 8-23; H-loge': 0.44-2.00) to low flow mussel habitats (S: 28-31; H-loge': 2.34-2.60).
Conclusions/Significance: Our data suggest that with increasing temperature and toxic hydrogen sulfide concentrations and increasing amplitude of variation of these factors, fewer species are able to cope with these extreme conditions. This results in less diverse communities in more extreme habitats. The finding of many species being present at sites with and without vent fluid emissions points to a non endemic deep-sea hydrothermal vent meiofaunal community. This is in contrast to a mostly endemic macrofauna but similar to what is known for meiofauna from shallow-water vents
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