12 research outputs found
Thermal behaviour of zircon/zirconia-added chemically durable borosilicate porous glass
Macroporous alkali resistant glass has been developed by making additions of zirconia (ZrO2) and zircon (ZrSiO4) to the sodium borosilicate glass system SiO2–B2O3 Na2O. The glass was made using a traditional high temperature fusion process. Differential thermal analysis (DTA) was carried out to identify the glass transition temperature (Tg) and crystallisation temperature (Tx). Based on these findings, controlled heat-treatments were implemented to separate the glass into two-phases; a silica-rich phase, and an alkali-rich borate phase. X-ray diffraction (XRD) was used to identify any crystal phases present in the asquenched and heat-treated glasses. Fourier transform infrared (FTIR) spectroscopy also proved effective in investigating phase separation and crystallisation behaviour. After leaching, a silica-rich skeleton with an interconnected pore structure and a uniform pore distribution was observed. Pore characterisation was carried out using mercury porosimetry. The size and shape of the pores largely depended on the heattreatment temperature and time. ZrO2/ZrSiO4 additions increased the alkali resistance of the porous glass 3–4 times
A2ML1 and otitis media: novel variants, differential expression, and relevant pathways
A genetic basis for otitis media is established, however, the role of rare variants in disease etiology is largely unknown. Previously a duplication variant within A2ML1 was identified as a significant risk factor for otitis media in an indigenous Filipino population and in US children. In this report exome and Sanger sequencing was performed using DNA samples from the indigenous Filipino population, Filipino cochlear implantees, US probands, Finnish, and Pakistani families with otitis media. Sixteen novel, damaging A2ML1 variants identified in otitis media patients were rare or low-frequency in population-matched controls. In the indigenous population, both gingivitis and A2ML1 variants including the known duplication variant and the novel splice variant c.4061 + 1 G>C were independently associated with otitis media. Sequencing of salivary RNA samples from indigenous Filipinos demonstrated lower A2ML1 expression according to the carriage of A2ML1 variants. Sequencing of additional salivary RNA samples from US patients with otitis media revealed differentially expressed genes that are highly correlated with A2ML1 expression levels. In particular, RND3 is upregulated in both A2ML1 variant carriers and high-A2ML1 expressors. These findings support a role for A2ML1 in keratinocyte differentiation within the middle ear as part of otitis media pathology and the potential application of ROCK inhibition in otitis media
FUT2 Variants Confer Susceptibility to Familial Otitis Media
Non-secretor status due to homozygosity for the common FUT2 variant c.461G>A (p.Trp154∗) is associated with either risk for autoimmune diseases or protection against viral diarrhea and HIV. We determined the role of FUT2 in otitis media susceptibility by obtaining DNA samples from 609 multi-ethnic families and simplex case subjects with otitis media. Exome and Sanger sequencing, linkage analysis, and Fisher exact and transmission disequilibrium tests (TDT) were performed. The common FUT2 c.604C>T (p.Arg202∗) variant co-segregates with otitis media in a Filipino pedigree (LOD = 4.0). Additionally, a rare variant, c.412C>T (p.Arg138Cys), is associated with recurrent/chronic otitis media in European-American children (p = 1.2 × 10−5) and US trios (TDT p = 0.01). The c.461G>A (p.Trp154∗) variant was also over-transmitted in US trios (TDT p = 0.01) and was associated with shifts in middle ear microbiota composition (PERMANOVA p 20 were combined, FUT2 variants were over-transmitted in trios (TDT p = 0.001). Fut2 is transiently upregulated in mouse middle ear after inoculation with non-typeable Haemophilus influenzae. Four FUT2 variants—namely p.Ala104Val, p.Arg138Cys, p.Trp154∗, and p.Arg202∗—reduced A antigen in mutant-transfected COS-7 cells, while the nonsense variants also reduced FUT2 protein levels. Common and rare FUT2 variants confer susceptibility to otitis media, likely by modifying the middle ear microbiome through regulation of A antigen levels in epithelial cells. Our families demonstrate marked intra-familial genetic heterogeneity, suggesting that multiple combinations of common and rare variants plus environmental factors influence the individual otitis media phenotype as a complex trait
Prolonged nasotracheal intubation or tracheostomy in acute laryngotrcheobronchitis and epiglottitis?
Definitions and methods to estimate regional land carbon fluxes for the second phase of the REgional Carbon Cycle Assessment and Processes Project (RECCAP-2)
International audienceRegional land carbon budgets provide insights into the spatial distribution of the land uptake of atmospheric carbon dioxide and can be used to evaluate carbon cycle models and to define baselines for land-based additional mitigation efforts. The scientific community has been involved in providing observation-based estimates of regional carbon budgets either by downscaling atmospheric CO2 observations into surface fluxes with atmospheric inversions, by using inventories of carbon stock changes in terrestrial ecosystems, by upscaling local field observations such as flux towers with gridded climate and remote sensing fields, or by integrating data-driven or process-oriented terrestrial carbon cycle models. The first coordinated attempt to collect regional carbon budgets for nine regions covering the entire globe in the RECCAP-1 project has delivered estimates for the decade 2000-2009, but these budgets were not comparable between regions due to different definitions and component fluxes being reported or omitted. The recent recognition of lateral fluxes of carbon by human activities and rivers that connect CO2 uptake in one area with its release in another also requires better definitions and protocols to reach harmonized regional budgets that can be summed up to a globe scale and compared with the atmospheric CO2 growth rate and inversion results. In this study, using the international initiative RECCAP-2 coordinated by the Global Carbon Project, which aims to be an update to regional carbon budgets over the last 2 decades based on observations for 10 regions covering the globe with a better harmonization than the precursor project, we provide recommendations for using atmospheric inversion results to match bottom-up carbon accounting and models, and we define the different component fluxes of the net land atmosphere carbon exchange that should be reported by each research group in charge of each region. Special attention is given to lateral fluxes, inland water fluxes, and land use fluxes
Epidemiology of equine grass sickness: a literature review (1909-1999)
The geographical spread of grass sickness between 1909 and 1999, particularly in England and Wales, is described, and the experimental investigations to identify a causal agent are summarised. The epidemiological techniques used to investigate grass sickness vary from clinical observations, to more advanced methods such as case-control studies using logistic regression analyses. Several risk factors for grass sickness have been reported consistently (age, time of year and recent movement to new pasture or premises) and several others have been reported for which the findings remain inconsistent (weather, pasture type, breed, supplementary feeding and use of anthelmintics)