91 research outputs found

    An investigation into the detection and identification of OsHV-1 µvar virus and associated risk factors causing mortalities in Crassostrea gigas in Ireland.

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    The Oyster Herpes Virus micro variant, OsHV-1μvar, is an emerging disease affecting Crassostrea gigas oysters which has caused significant mortalities in France, Ireland, and the UK (Jersey and Kent, England) between the summer of 2008 and 2012.The present MSc. study was carried out in 2 parts. The first part of the study aimed to characterize and further elucidate the strains of OsHV-1 present in C. gigas oysters sampled in Ireland by further examining sequence data obtained from animals collected from 30 bays during mortality outbreaks between 2003-2012. Part two of this study investigated the detection of OsHV-1 µvar and associated risk factors during mortality outbreaks. The current study provides some insights into mortality events affecting farmed Pacific oyster production in Ireland. The epidemiological study conducted found that batch mortality was lower in 2011, compared with earlier years, in association with lower OsHV-1 µvar viral loads

    Evaluation of epidemiological cut-off values indicates that biocide resistant subpopulations are uncommon in natural isolates of clinically-relevant microorganisms

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    To date there are no clear criteria to determine whether a microbe is susceptible to biocides or not. As a starting point for distinguishing between wild-type and resistant organisms, we set out to determine the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) distributions for four common biocides; triclosan, benzalkonium chloride, chlorhexidine and sodium hypochlorite for 3319 clinical isolates, with a particular focus on Staphylococcus aureus (N = 1635) and Salmonella spp. (N = 901) but also including Escherichia coli (N = 368), Candida albicans (N = 200), Klebsiella pneumoniae (N = 60), Enterobacter spp. (N = 54), Enterococcus faecium (N = 53), and Enterococcus faecalis (N = 56). From these data epidemiological cut-off values (ECOFFs) are proposed. As would be expected, MBCs were higher than MICs for all biocides. In most cases both values followed a normal distribution. Bimodal distributions, indicating the existence of biocide resistant subpopulations were observed for Enterobacter chlorhexidine susceptibility (both MICs and MBCs) and the susceptibility to triclosan of Enterobacter (MBC), E. coli (MBC and MIC) and S. aureus (MBC and MIC). There is a concern on the potential selection of antibiotic resistance by biocides. Our results indicate however that resistance to biocides and, hence any potential association with antibiotic resistance, is uncommon in natural populations of clinically relevant microorganisms. \ua9 2014 Morrissey et al

    Sphingolipids in the Root Play an Important Role in Regulating the Leaf Ionome in \u3ci\u3eArabidopsis thaliana\u3c/i\u3e

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    Sphingolipid synthesis is initiated by condensation of Ser with palmitoyl-CoA producing 3-ketodihydrosphinganine (3-KDS), which is reduced by a 3-KDS reductase to dihydrosphinganine. Ser palmitoyltransferase is essential for plant viability. Arabidopsis thaliana contains two genes (At3g06060/TSC10A and At5g19200/TSC10B) encoding proteins with significant similarity to the yeast 3-KDS reductase, Tsc10p. Heterologous expression in yeast of either Arabidopsis gene restored 3-KDS reductase activity to the yeast tsc10D mutant, confirming both as bona fide 3-KDS reductase genes. Consistent with sphingolipids having essential functions in plants, double mutant progeny lacking both genes were not recovered from crosses of single tsc10A and tsc10B mutants. Although the 3-KDS reductase genes are functionally redundant and ubiquitously expressed in Arabidopsis, 3-KDS reductase activity was reduced to 10% of wild-type levels in the loss-of-function tsc10a mutant, leading to an altered sphingolipid profile. This perturbation of sphingolipid biosynthesis in the Arabidopsis tsc10a mutant leads an altered leaf ionome, including increases in Na, K, and Rb and decreases in Mg, Ca, Fe, and Mo. Reciprocal grafting revealed that these changes in the leaf ionome are driven by the root and are associated with increases in root suberin and alterations in Fe homeostasis

    Las TIC del aula a la agenda política : ponencias del Seminario internacional Cómo las TIC transforman las escuelas

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    ¿Qué razones impulsan la necesidad de la inclusión de las Tecnologías de la Información y la Comunicación en el sistema educativo? ¿Pueden estas tecnologías contribuir al cumplimiento de los objetivos educativos, propuestos por el Estado, de equidad y calidad para todos? ¿Cuál es el papel del Estado en la inclusión de TIC en la educación y en las instituciones educativas? El Seminario internacional “Cómo las TIC transforman las escuelas”, realizado en abril de 2007 en la Ciudad de Buenos Aires, apuntó a responder estas preguntas, además de abrir algunos temas fuertemente relacionados, como el de la integración curricular de las TIC, la gestión en las instituciones educativas y el software de código abierto, entre otros. El Seminario fue organizado por UNICEF Argentina y el IIPE-UNESCO, Sede Regional Buenos Aires, con el objetivo de contribuir al debate y la reflexión sobre la inclusión de las TIC en el ámbito educativo en su perspectiva política y pedagógica. Este volumen presenta los aportes que prestigiosos especialistas internacionales y nacionales han compartido con una nutrida audiencia de funcionarios públicos, directivos y docentes de todos los niveles de la educación

    Copper-Triggered Aggregation of Ubiquitin

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    Neurodegenerative disorders share common features comprising aggregation of misfolded proteins, failure of the ubiquitin-proteasome system, and increased levels of metal ions in the brain. Protein aggregates within affected cells often contain ubiquitin, however no report has focused on the aggregation propensity of this protein. Recently it was shown that copper, differently from zinc, nickel, aluminum, or cadmium, compromises ubiquitin stability and binds to the N-terminus with 0.1 micromolar affinity. This paper addresses the role of copper upon ubiquitin aggregation. In water, incubation with Cu(II) leads to formation of spherical particles that can progress from dimers to larger conglomerates. These spherical oligomers are SDS-resistant and are destroyed upon Cu(II) chelation or reduction to Cu(I). In water/trifluoroethanol (80∶20, v/v), a mimic of the local decrease in dielectric constant experienced in proximity to a membrane surface, ubiquitin incubation with Cu(II) causes time-dependent changes in circular dichroism and Fourier-transform infrared spectra, indicative of increasing β-sheet content. Analysis by atomic force and transmission electron microscopy reveals, in the given order, formation of spherical particles consistent with the size of early oligomers detected by gel electrophoresis, clustering of these particles in straight and curved chains, formation of ring structures, growth of trigonal branches from the rings, coalescence of the trigonal branched structures in a network. Notably, none of these ubiquitin aggregates was positive to tests for amyloid and Cu(II) chelation or reduction produced aggregate disassembly. The early formed Cu(II)-stabilized spherical oligomers, when reconstituted in 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes and in POPC planar bilayers, form annular and pore-like structures, respectively, which are common to several neurodegenerative disorders including Parkinson's, Alzheimer's, amyotrophic lateral sclerosis, and prion diseases, and have been proposed to be the primary toxic species. Susceptibility to aggregation of ubiquitin, as it emerges from the present study, may represent a potential risk factor for disease onset or progression while cells attempt to tag and process toxic substrates

    'Arranged' Marriage, Dowry and Female Literacy in a Transitional Society

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    Aid, Debt Burden and Government Fiscal Behaviour in Cote d'Ivoire

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