282 research outputs found
Brug over de Zeeschelde te Temse/Bornem: hydraulische en nautische studie van het voorontwerp
Tank test of vessel entry and exit for third set of Panama locks
The Panama Canal Authority (ACP) plans to extend the capacity of and allow larger ships to the Canal by building a so-called third lane, consisting of a new set of locks parallel to the existing ones. The design ship is a so-called Post-Panamax 12000 TEU container carrier. In order to optimise the approach to and the manoeuvres within the locks, in 2007-2008 experimental research has been conducted at Flanders Hydraulics Research, Antwerp, Belgium on a 1/80 scale model of the approach lane, the lock and the design vessel. With the ship model moving along a guiding rail, lateral forces acting on the ship and movements of the vessel can be recorded during a selection of entrance and exit manoeuvres. During a number of tests, the effect of density exchange current was examined. The present article offers an overview of the test-setup with a discussion of a few interesting results of the test runs
Determining residual CO(2) saturation through a dissolution test - Results from the CO2CRC Otway Project
Residual CO2 trapping (Sgr-CO2) is a key mechanism for geological CO2 storage. The CO2CRC undertook a sequence of field tests with the aim of comparing different ways of determining Sgr-CO2 including a dissolution test. Dissolution test results show an unexpectedly early breakthrough and low maximum CO2 concentrations in the back- produced water making the data inconclusive when using traditional data interpretation. Here, we consider two conditions to explain the observations: Firstly, residual CO2 is vertically unevenly distributed and, secondly, the fluid and residual CO2 are not in equilibrium. Furthermore, we postulate localised flow channels have formed during the 3- month test period caused by advective flow of CO2-saturated, low pH water leading to transport-controlled mineral dissolution.R.R. Haese, T. LaForce, C. Boreham, J. Ennis-King, B.M. Freifeld, L. Paterson, U. Schach
Downregulation of exosomal miR-204-5p and miR-632 as a biomarker for FTD: a GENFI study
OBJECTIVE: To determine whether exosomal microRNAs (miRNAs) in cerebrospinal fluid (CSF) of patients with frontotemporal dementia (FTD) can serve as diagnostic biomarkers, we assessed miRNA expression in the Genetic Frontotemporal Dementia Initiative (GENFI) cohort and in sporadic FTD. METHODS: GENFI participants were either carriers of a pathogenic mutation in progranulin, chromosome 9 open reading frame 72 or microtubule-associated protein tau or were at risk of carrying a mutation because a first-degree relative was a known symptomatic mutation carrier. Exosomes were isolated from CSF of 23 presymptomatic and 15 symptomatic mutation carriers and 11 healthy non-mutation carriers. Expression of 752 miRNAs was measured using quantitative PCR (qPCR) arrays and validated by qPCR using individual primers. MiRNAs found differentially expressed in symptomatic compared with presymptomatic mutation carriers were further evaluated in a cohort of 17 patients with sporadic FTD, 13 patients with sporadic Alzheimer's disease (AD) and 10 healthy controls (HCs) of similar age. RESULTS: In the GENFI cohort, miR-204-5p and miR-632 were significantly decreased in symptomatic compared with presymptomatic mutation carriers. Decrease of miR-204-5p and miR-632 revealed receiver operator characteristics with an area of 0.89 (90% CI 0.79 to 0.98) and 0.81 (90% CI 0.68 to 0.93), respectively, and when combined an area of 0.93 (90% CI 0.87 to 0.99). In sporadic FTD, only miR-632 was significantly decreased compared with AD and HCs. Decrease of miR-632 revealed an area of 0.90 (90% CI 0.81 to 0.98). CONCLUSIONS: Exosomal miR-204-5p and miR-632 have potential as diagnostic biomarkers for genetic FTD and miR-632 also for sporadic FTD
Overview of the CO2CRC Otway residual saturation and dissolution test
Residual and dissolution trapping are important mechanisms for secure geological storage of carbon dioxide. When appraising a potential site, it is desirable to have accurate field-scale estimates of the proportion of trapping by these mechanisms. For this purpose a short single-well test has been conceived that could be implemented before large- scale injection. To test this concept in the field, a residual saturation and dissolution test sequence was conducted at the CO2CRC Otway site during 2011. The test involved injection of 150 tonnes of pure carbon dioxide followed by 454 tonnes of formation water to drive the carbon dioxide to residual saturation. A variety of methods for measuring saturation were applied to the injection zone so the results could be compared. Here we provide an overview of the field-test sequence and the measurement methods.Lincoln Paterson, Chris Boreham, Mark Bunch, Tess Dance, Jonathan Ennis-King, Barry Freifeld, Ralf Haese, Charles Jenkins, Tara LaForce, Matthias Raab, Rajindar Singh, Linda Stalker and Yingqi Zhan
Public Health Impact After the Introduction of PsA-TT: The First 4 Years.
BACKGROUND: During the first introduction of a group A meningococcal vaccine (PsA-TT) in 2010-2011 and its rollout from 2011 to 2013, >150 million eligible people, representing 12 hyperendemic meningitis countries, have been vaccinated. METHODS: The new vaccine effectiveness evaluation framework was established by the World Health Organization and partners. Meningitis case-based surveillance was strengthened in PsA-TT first-introducer countries, and several evaluation studies were conducted to estimate the vaccination coverage and to measure the impact of vaccine introduction on meningococcal carriage and disease incidence. RESULTS: PsA-TT implementation achieved high vaccination coverage, and results from studies conducted showed significant decrease of disease incidence as well as significant reduction of oropharyngeal carriage of group A meningococci in vaccinated and unvaccinated individuals, demonstrating the vaccine's ability to generate herd protection and prevent group A epidemics. CONCLUSIONS: Lessons learned from this experience provide useful insights in how to guide and better prepare for future new vaccine introductions in resource-limited settings
Bi-fluorescent Staphylococcus aureus infection enables single-cell analysis of intracellular killing in vivo
Techniques for studying the clearance of bacterial infections are critical for advances in understanding disease states, immune cell effector functions, and novel antimicrobial therapeutics. Intracellular killing of Staphylococcus aureus by neutrophils can be monitored using a S. aureus strain stably expressing GFP, a fluorophore that is quenched when exposed to the reactive oxygen species (ROS) present in the phagolysosome. Here, we expand upon this method by developing a bi-fluorescent S. aureus killing assay for use in vivo. Conjugating S. aureus with a stable secondary fluorescent marker enables the separation of infected cell samples into three populations: cells that have not engaged in phagocytosis, cells that have engulfed and killed S. aureus, and cells that have viable internalized S. aureus. We identified ATTO647N-NHS Ester as a favorable dye conjugate for generating bi-fluorescent S. aureus due to its stability over time and invariant signal within the neutrophil phagolysosome. To resolve the in vivo utility of ATTO647N/GFP bi-fluorescent S. aureus, we evaluated neutrophil function in a murine model of chronic granulomatous disease (CGD) known to have impaired clearance of S. aureus infection. Analysis of bronchoalveolar lavage (BAL) from animals subjected to pulmonary infection with bi-fluorescent S. aureus demonstrated differences in neutrophil antimicrobial function consistent with the established phenotype of CGD
Downregulation of exosomal miR-204-5p and miR-632 as a biomarker for FTD: A GENFI study
Objective: To determine whether exosomal microRNAs (miRNAs) in cerebrospinal fluid (CSF) of patients with frontotemporal dementia (FTD) can serve as diagnostic biomarkers, we assessed miRNA expression in the Genetic Frontotemporal Dementia Initiative (GENFI) cohort and in sporadic FTD. Methods: GENFI participants were either carriers of a pathogenic mutation in progranulin, chromosome 9 open reading frame 72 or microtubule-associated protein tau or were at risk of carrying a mutation because a first-degree relative was a known symptomatic mutation carrier. Exosomes were isolated from CSF of 23 presymptomatic and 15 symptomatic mutation carriers and 11 healthy non-mutation carriers. Expression of 752 miRNAs was measured using quantitative PCR (qPCR) arrays and validated by qPCR using individual primers. MiRNAs found differentially expressed in symptomatic compared with presymptomatic mutation carriers were further evaluated in a cohort of 17 patients with sporadic FTD, 13 patients with sporadic Alzheimer's disease (AD) and 10 healthy controls (HCs) of similar age. Results: In the GENFI cohort, miR-204-5p and miR-632 were significantly decreased in symptomatic compared with presymptomatic mutation carriers. Decrease of miR-204-5p and miR-632 revealed receiver operator characteristics with an area of 0.89 (90% CI 0.79 to 0.98) and 0.81 (90% CI 0.68 to 0.93), respectively, and when combined an area of 0.93 (90% CI 0.87 to 0.99). In sporadic FTD, only miR-632 was significantly decreased compared with AD and HCs. Decrease of miR-632 revealed an area of 0.90 (90% CI 0.81 to 0.98). Conclusions: Exosomal miR-204-5p and miR-632 have potential as diagnostic biomarkers for genetic FTD and miR-632 also for sporadic FTD
The Case for Reactive Mass Oral Cholera Vaccinations
Cholera outbreaks have had catastrophic impact on societies for centuries. Despite more than half a century of advocacy for safe water, sanitation and hygiene, approximately 100,000 cholera cases and 5,000 deaths were reported in Zimbabwe between August 2008 and by July 2009. Safe and effective oral cholera vaccines have been licensed and used by affluent tourists for more than a decade to prevent cholera. We asked whether oral cholera vaccines could be used to protect high risk populations at a time of cholera. We calculated how many cholera cases could have been prevented if mass cholera vaccinations would have been implemented in reaction to past cholera outbreaks. We estimate that determined, well organized mass vaccination campaigns could have prevented 34,900 (40%) cholera cases and 1,695 deaths (40%) in Zimbabwe. In the sites with endemic cholera, Kolkata and Zanzibar, a significant number of cases could have been prevented but the impact would have been less dramatic. The barriers which currently prevent the implementation of mass vaccinations, including but not only the cost to purchase the vaccine, seem insurmountable. A concerted effort of donors and key decision makers will be needed to offer better protection to populations at risk
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