430 research outputs found

    The effect of flux emergence from the solar surface to the corona

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    In this thesis I have explored some of the ways in which the contexts of epistemology, ethics and designing architecture are each concerned with undecidable questions (that is, with those questions that have no right answers). Drawing on design research, second‐order cybernetics and radical constructivism, I have understood this undecidability to follow in each case from our being part of the situation in which we are acting. This idea is primarily epistemological (being part of the world we observe, we cannot verify the relationship between our understanding and the world beyond our experience as it is impossible to observe the latter) but can also be interpreted spatially and ethically. From this starting point I have developed connections between questions in architecture, epistemology and ethics in two parallel investigations. In the first, I have proposed a connection between design and ethics where design is understood as an activity in which ethical questioning is implicit. Rather than the usual application of ethical theory to practice, I have instead proposed that design can inform ethical thinking, both in the context of designing architecture and also more generally, through (1) the ways designers approach what Rittel (1972) called “wicked problems” (which, I argue, have the same structure as ethical dilemmas) and (2) the implicit consideration of others in design’s core methodology. In parallel to this I have explored the spatial sense of the idea that we are part of the world through a series of design investigations comprising projects set in everyday situations and other speculative drawings. Through these I have proposed reformulating the architectural theme of place, which is usually associated with phenomenology, in constructivist terms as the spatiality of observing our own observing and so as where the self‐reference of epistemology (that we cannot experience the world beyond our experience) becomes manifest

    Using a genetically informative design to examine the relationship between breastfeeding and childhood conduct problems

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    A number of public health interventions aimed at increasing the uptake of breastfeeding are in place in the United States and other Western countries. While the physical health and nutritional benefits of breastfeeding for the mother and child are relatively well established, the evidence for psychological effects is less clear. This study aimed to examine whether there is an association between breastfeeding and later conduct problems in children. It also considered the extent to which any relationship is attributable to maternally-provided inherited characteristics that influence both likelihood of breastfeeding and child conduct problems. A prenatal cross-fostering design with a sample of 870 families with a child aged 4–11 years was used. Mothers were genetically related or unrelated to their child as a result of assisted reproductive technologies. The relationship between breastfeeding and conduct problems was assessed while controlling for theorised measured confounders by multivariate regression (e.g. maternal smoking, education, and antisocial behaviour), and for unmeasured inherited factors by testing associations separately for related and unrelated mother-child pairs. Breastfeeding was associated with lower levels of conduct disorder symptoms in offspring in middle childhood. Breastfeeding was associated with lower levels of conduct problems even after controlling for observed confounders in the genetically related group, but not in the genetically unrelated group. In contrast, maternal antisocial behaviour showed robust associations with child conduct problems after controlling for measured and inherited confounders. These findings highlight the importance of using genetically sensitive designs in order to test causal environmental influences

    Evaluation of the in vitro skin permeation of antiviral drugs from penciclovir 1% cream and acyclovir 5% cream used to treat herpes simplex virus infection

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    <p>Abstract</p> <p>Background</p> <p>Herpes simplex virus infection (HSV) is a common and ubiquitous infection of the skin which causes mucocutaneous lesions called cold sores (herpes labialis) or fever blisters. It is estimated that approximately 80% of the population worldwide are carriers of the Herpes simplex virus, approximately 40% suffer from recurrent recurrent infections. This study evaluates the <it>in vitro </it>skin permeation and penetration of penciclovir and acyclovir from commercialized creams for the treatment of herpes labialis (cold sores), using non viable excised human abdominal skin samples, which were exposed to 5 mg/cm<sup>2 </sup>of acyclovir 5% cream or penciclovir 1% cream.</p> <p>Methods</p> <p>After 24 h of cream application, excess cream was washed off and layers of stratum corneum were removed by successive tape stripping. Amounts of active ingredients having penetrated through the skin were measured, as well as the amounts in the washed-off cream, in skin strips and creams remaining in the skin. Molecular modelling was used to evaluate physico-chemical differences between the drugs. Western blot analysis enabled to determine whether the marker of basal cells keratin 5 could be detected in the various tape strips.</p> <p>Results</p> <p>Application of penciclovir 1% cream yielded higher concentration of drug in the deeper layers of the epidermis as well as a higher drug flux through the skin. Molecular modelling showed two higher hydrophobic moieties for acyclovir. Presence of the basal cell marker keratin 5 was underscored in the deeper tape strips from the skin, giving evidence that both drugs can reach their target cells.</p> <p>Conclusion</p> <p>Penciclovir 1% cream has the tendency to facilitate the diffusion of the drug through the stratum corneum into the deeper epidermis layers, in which it could reach the target basal cells at effective therapeutical concentration. The small difference in the surface properties between both molecules might also contribute to favour the passage of penciclovir through the epidermis into the deeper basal cells.</p

    Overexpression of miR-128 specifically inhibits the truncated isoform of NTRK3 and upregulates BCL2 in SH-SY5Y neuroblastoma cells

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    <p>Abstract</p> <p>Background</p> <p>Neurotrophins and their receptors are key molecules in the regulation of neuronal differentiation and survival. They mediate the survival of neurons during development and adulthood and are implicated in synaptic plasticity. The human neurotrophin-3 receptor gene <it>NTRK3 </it>yields two major isoforms, a full-length kinase-active form and a truncated non-catalytic form, which activates a specific pathway affecting membrane remodeling and cytoskeletal reorganization. The two variants present non-overlapping 3'UTRs, indicating that they might be differentially regulated at the post-transcriptional level. Here, we provide evidence that the two isoforms of <it>NTRK3 </it>are targeted by different sets of microRNAs, small non-coding RNAs that play an important regulatory role in the nervous system.</p> <p>Results</p> <p>We identify one microRNA (miR-151-3p) that represses the full-length isoform of <it>NTRK3 </it>and four microRNAs (miR-128, miR-485-3p, miR-765 and miR-768-5p) that repress the truncated isoform. In particular, we show that the overexpression of miR-128 - a brain enriched miRNA - causes morphological changes in SH-SY5Y neuroblastoma cells similar to those observed using an siRNA specifically directed against truncated <it>NTRK3</it>, as well as a significant increase in cell number. Accordingly, transcriptome analysis of cells transfected with miR-128 revealed an alteration of the expression of genes implicated in cytoskeletal organization as well as genes involved in apoptosis, cell survival and proliferation, including the anti-apoptotic factor <it>BCL2</it>.</p> <p>Conclusions</p> <p>Our results show that the regulation of <it>NTRK3 </it>by microRNAs is isoform-specific and suggest that neurotrophin-mediated processes are strongly linked to microRNA-dependent mechanisms. In addition, these findings open new perspectives for the study of the physiological role of miR-128 and its possible involvement in cell death/survival processes.</p

    Is Aquatic Life Correlated with an Increased Hematocrit in Snakes?

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    Background: Physiological adaptations that allow air-breathing vertebrates to remain underwater for long periods mainly involve modifications of the respiratory system, essentially through increased oxygen reserves. Physiological constraints on dive duration tend to be less critical for ectotherms than for endotherms because the former have lower mass-specific metabolic rates. Moreover, comparative studies between marine and terrestrial ectotherms have yet to show overall distinct physiological differences specifically associated with oxygen reserves. Methodology/Principal Findings: We used phylogenetically informed statistical models to test if habitat affects hematocrit (an indicator of blood oxygen stores) in snakes, a lineage that varies widely in habitat use. Our results indicate that both phylogenetic position (clade) and especially habitat are significant predictors of hematocrit. Our analysis also confirms the peculiar respiratory physiology of the marine Acrochordus granulatus. Conclusion/Significance: Contrary to previous findings, marine snakes have significantly–albeit slightly–elevated hematocrit, which should facilitate increased aerobic dive times. Longer dives could have consequences for foraging, mate searching, and predation risks. Alternatively, but not exclusively, increased Hct in marine species might also help t

    Selective inhibition of tropomyosin-receptor-kinase A (TrkA) reduces pain and joint damage in two rat models of inflammatory arthritis

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    Background: Inflammation is an essential component of arthritis pain. Nerve growth factor (NGF) plays a key role in acute and chronic pain states especially those associated with inflammation. NGF acts through tropomyosin-receptor-kinase A (TrkA). NGF blockade has reduced arthritis pain in clinical trials. We explored the mechanisms within the joint which may contribute to the analgesic effects of NGF by selectively inhibiting TrkA in carrageenan-induced or collagen-induced joint pain behaviour. The goal of the current study was to elucidate whether inflammation is central to the efficacy for NGF blockade. Methods: Rats were injected in their left knees with 2 % carrageenan or saline. Collagen-induced arthritis (CIA) was induced by intradermal injections of a mixture of bovine type II collagen (0.2 mg) and incomplete Freund’s adjuvant (0.2 mg). Oral doses (30 mg/kg) of AR786 or vehicle control were given twice daily after arthritis induction. Ibuprofen-treated (35 mg/kg, orally, once daily) rats with CIA were used as positive analgesic controls. Pain behaviour was measured as hind-limb weight-bearing asymmetry and hind-paw withdrawal thresholds to von Frey hair stimulation (carrageenan synovitis), or withdrawal to joint compression using a Randall Selitto device (CIA). Inflammation was measured as increased knee joint diameter and by histopathological analysis. Results: Intra-articular injections of carrageenan or induction of CIA was each associated with pain behaviour and synovial inflammation. Systemic administration of the TrkA inhibitor AR786 reduced carrageenan-induced or CIA-induced pain behaviour to control values, and inhibited joint swelling and histological evidence of synovial inflammation and joint damage. Conclusions: By using two models of varying inflammation we demonstrate for the first time that selective inhibition of TrkA may reduce carrageenan-induced or CIA-induced pain behaviour in rats, in part through potentially inhibiting synovial inflammation, although direct effects on sensory nerves are also likely. Our observations suggest that inflammatory arthritis causes pain and the presence of inflammation is fundamental to the beneficial effects (reduction in pain and pathology) of NGF blockade. Further research should determine whether TrkA inhibition may ameliorate human inflammatory arthritis

    Genetic Diversity and Antimicrobial Resistance of Escherichia coli from Human and Animal Sources Uncovers Multiple Resistances from Human Sources

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    Escherichia coli are widely used as indicators of fecal contamination, and in some cases to identify host sources of fecal contamination in surface water. Prevalence, genetic diversity and antimicrobial susceptibility were determined for 600 generic E. coli isolates obtained from surface water and sediment from creeks and channels along the middle Santa Ana River (MSAR) watershed of southern California, USA, after a 12 month study. Evaluation of E. coli populations along the creeks and channels showed that E. coli were more prevalent in sediment compared to surface water. E. coli populations were not significantly different (P = 0.05) between urban runoff sources and agricultural sources, however, E. coli genotypes determined by pulsed-field gel electrophoresis (PFGE) were less diverse in the agricultural sources than in urban runoff sources. PFGE also showed that E. coli populations in surface water were more diverse than in the sediment, suggesting isolates in sediment may be dominated by clonal populations.Twenty four percent (144 isolates) of the 600 isolates exhibited resistance to more than one antimicrobial agent. Most multiple resistances were associated with inputs from urban runoff and involved the antimicrobials rifampicin, tetracycline, and erythromycin. The occurrence of a greater number of E. coli with multiple antibiotic resistances from urban runoff sources than agricultural sources in this watershed provides useful evidence in planning strategies for water quality management and public health protection

    Recognising Victimhood: Lessons from the International Criminal Court and Mass Claim Programmes for the Compensation Procedure Parallel to the Trial of International Crimes in the Netherlands

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    In the Netherlands, the Dutch criminal court in The Hague (hereinafter: ‘Netherlands International Crimes Court’ or ‘NIC court’) is assigned to try international crimes, and to provide compensation to victims of such crimes. Whereas it has specific criminal laws at its disposal to try international crimes, it applies ‘regular’ Dutch civil law to assess claims for compensation. Yet compensation for international crimes entails challenges that are quite different from domestic crimes: international crimes are normally committed against a large number of victims, and frequently result in bodily harm. This article argues that the NIC court will most likely rule a large number of claims for compensation inadmissible, as a consequence of which victims cannot benefit from the advantages inherent in the award of compensation within the criminal process. It then explores the adjudicative and reparatory standards that the International Criminal Court and mass claim programmes have applied to simplify both the adjudication of a large number of claims, and the calculation of a large number of instances of bodily damage. It is submitted that adoption by the NIC court of international reparatory standards could facilitate the assessment of a large number of civil claims within the criminal process, without prejudice to the legitimate interests of the defendant for an adequate procedure. However, these standards require the NIC court to strike a new balance between tailor-made compensation and symbolic compensation, and thereby between corrective justice and restorative justice

    Exposure to GSM RF fields does not affect calcium homeostasis in human endothelial cells, rat pheocromocytoma cells or rat hippocampal neurons

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    In the course of modern daily life, individuals are exposed to numerous sources of electromagnetic radiation that are not present in the natural environment. The strength of the electromagnetic fields from sources such as hairdryers, computer display units and other electrical devices is modest. However, in many home and office environments, individuals can experience perpetual exposure to an "electromagnetic smog", with occasional peaks of relatively high electromagnetic field intensity. This has led to concerns that such radiation can affect health. In particular, emissions from mobile phones or mobile phone masts have been invoked as a potential source of pathological electromagnetic radiation. Previous reports have suggested that cellular calcium (Ca2+) homeostasis is affected by the types of radiofrequency fields emitted by mobile phones. In the present study, we used a high-throughput imaging platform to monitor putative changes in cellular Ca2+ during exposure of cells to 900 MHz GSM fields of differing power (specific absorption rate 0.012-2 W/Kg), thus mimicking the type of radiation emitted by current mobile phone handsets. Data from cells experiencing the 900 Mhz GSM fields were compared with data obtained from paired experiments using continuous wave fields or no field. We employed three cell types (human endothelial cells, PC-12 neuroblastoma and primary hippocampal neurons) that have previously been suggested to be sensitive to radiofrequency fields. Experiments were designed to examine putative effects of radiofrequency fields on resting Ca2+, in addition to Ca2+ signals evoked by an InsP(3)-generating agonist. Furthermore, we examined putative effects of radiofrequency field exposure on Ca2+ store emptying and store-operated Ca2+ entry following application of the Ca2+ATPase inhibitor thapsigargin. Multiple parameters (e.g., peak amplitude, integrated Ca2+ signal, recovery rates) were analysed to explore potential impact of radiofrequency field exposure on Ca2+ signals. Our data indicate that 900 MHz GSM fields do not affect either basal Ca2+ homeostasis or provoked Ca2+ signals. Even at the highest field strengths applied, which exceed typical phone exposure levels, we did not observe any changes in cellular Ca2+ signals. We conclude that under the conditions employed in our experiments, and using a highly-sensitive assay, we could not detect any consequence of RF exposure
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