8,453 research outputs found

    Making the best use of consultants in the GCC

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    Falling oil prices have forced the GCC countries to revise or, in the case of Saudi Arabia, launch their economic visions, creating a potentially important role for consultants. According to Global Research Saudi Arabia’s consulting market expanded by 14.8 percent to $1.25 billion in 2015, accounting for almost half of the robust GCC consulting market, which itself grew by 9.4 percent. How can the GCC countries get the best out of the expert advice on offer

    Investigating the impact of reservoir properties and injection parameters on carbon dioxide dissolution in saline aquifers

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    CO2 injection into geological formations is considered one way of mitigating the increasing levels of carbon dioxide concentrations in the atmosphere and its effect on and global warming. In regard to sequestering carbon underground, different countries have conducted projects at commercial scale or pilot scale and some have plans to develop potential storage geological formations for carbon dioxide storage. In this study, pure CO2 injection is examined on a model with the properties of bunter sandstone and then sensitivity analyses were conducted for some of the fluid, rock and injection parameters. The results of this study show that the extent to which CO2 has been convected in the porous media in the reservoir plays a vital role in improving the CO2 dissolution in brine and safety of its long term storage. We conclude that heterogeneous permeability plays a crucial role on the saturation distribution and can increase or decrease the amount of dissolved CO2 in water around ± 7% after the injection stops and up to 13% after 120 years. Furthermore, the value of absolute permeability controls the effect of the Kv/Kh ratio on the CO2 dissolution in brine. In other words, as the value of vertical and horizontal permeability decreases (i.e., tight reservoirs) the impact of Kv/Kh ratio on the dissolved CO2 in brine becomes more prominent. Additionally, reservoir engineering parameters, such as well location, injection rate and scenarios, also have a high impact on the amount of dissolved CO2 and can change the dissolution up to 26%, 100% and 5.5%, respectively

    Precision Astrometry of a Sample of Speckle Binaries and Multiples with the Adaptive Optics Facilities at the Hale and Keck II Telescopes

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    Using the adaptive optics facilities at the 200-in Hale and 10-m Keck II, we observed in the near infrared a sample of 12 binary and multiple stars and one open cluster. We used the near diffraction limited images of these systems to measure the relative separations and position angles between their components. In this paper, we investigate and correct for the influence of the differential chromatic refraction and chip distortions on our relative astrometric measurements. Over one night, we achieve an astrometric precision typically well below 1 miliarcsecond and occasionally as small as 40 microarcseconds. Such a precision is in principle sufficient to astrometrically detect planetary mass objects around the components of nearby binary and multiple stars. Since we have not had sufficiently large data sets for the observed sample of stars to detect planets, we provide the limits to planetary mass objects based on the obtained astrometric precision.Comment: 18 pages, 8 figures, 9 tables, to appear in MNRA

    From regional pulse vaccination to global disease eradication: insights from a mathematical model of Poliomyelitis

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    Mass-vaccination campaigns are an important strategy in the global fight against poliomyelitis and measles. The large-scale logistics required for these mass immunisation campaigns magnifies the need for research into the effectiveness and optimal deployment of pulse vaccination. In order to better understand this control strategy, we propose a mathematical model accounting for the disease dynamics in connected regions, incorporating seasonality, environmental reservoirs and independent periodic pulse vaccination schedules in each region. The effective reproduction number, ReR_e, is defined and proved to be a global threshold for persistence of the disease. Analytical and numerical calculations show the importance of synchronising the pulse vaccinations in connected regions and the timing of the pulses with respect to the pathogen circulation seasonality. Our results indicate that it may be crucial for mass-vaccination programs, such as national immunisation days, to be synchronised across different regions. In addition, simulations show that a migration imbalance can increase ReR_e and alter how pulse vaccination should be optimally distributed among the patches, similar to results found with constant-rate vaccination. Furthermore, contrary to the case of constant-rate vaccination, the fraction of environmental transmission affects the value of ReR_e when pulse vaccination is present.Comment: Added section 6.1, made other revisions, changed titl

    A thermoresponsive and magnetic colloid for 3D cell expansion and reconfiguration

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    A dual thermoresponsive and magnetic colloidal gel matrix is described for enhanced stem-cell culture. The combined properties of the material allow enzyme-free passaging and expansion of mesenchymal stem cells, as well as isolation of cells postculture by the simple process of lowering the temperature and applying an external magnetic field. The colloidal gel can be reconfigured with thermal and magnetic stimuli to allow patterning of cells in discrete zones and to control movement of cells within the porous matrix during culture

    Epidemiology and outcomes of out-of-hospital cardiac arrest in Qatar : A nationwide observational study

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    This is a pre-copyedited, author-produced pdf of an article accepted for publication in International Journal of Cardiology following peer review. The version of record, 'Epidemiology and outcomes of out-of-hospital cardiac arrest in Qatar: A nationwide observational study', F. B. Irfan, et.a., International Journal of Cardiology, Vol 223, pp 1007-1013, November 2016, first published on line on August 24, 2016, is available on line via doi: http;//dx.doi.org/10.1016/j.ijcard.2016.08.299 © 2016 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Background Out-of-hospital cardiac arrest (OHCA) studies from the Middle East and Asian region are limited. This study describes the epidemiology, emergency health services, and outcomes of OHCA in Qatar. Methods This was a prospective nationwide population-based observational study on OHCA patients in Qatar according to Utstein style guidelines, from June 2012 to May 2013. Data was collected from various sources; the national emergency medical service, 4 emergency departments, and 8 public hospitals. Results The annual crude incidence of presumed cardiac OHCA attended by EMS was 23.5 per 100,000. The age-sex standardized incidence was 87.8 per 100,000 population. Of the 447 OHCA patients included in the final analysis, most were male (n = 360, 80.5%) with median age of 51 years (IQR = 39–66). Frequently observed nationalities were Qatari (n = 89, 19.9%), Indian (n = 74, 16.6%) and Nepalese (n = 52, 11.6%). Bystander cardiopulmonary resuscitation (CPR) was carried out in 92 (20.6%) OHCA patients. Survival rate was 8.1% (n = 36) and multivariable logistic regression indicated that initial shockable rhythm (OR 13.4, 95% CI 5.4–33.3, p = 0.001) was associated with higher odds of survival while male gender (OR 0.27, 95% CI 0.1–0.8, p = 0.01) and advanced cardiac life support (ACLS) (OR 0.15, 95% CI 0.04–0.5, p = 0.02) were associated with lower odds of survival. Conclusions Standardized incidence and survival rates were comparable to Western countries. Although expatriates comprise more than 80% of the population, Qataris contributed 20% of the total cardiac arrests observed. There are significant opportunities to improve outcomes, including community-based CPR and defibrillation training.Peer reviewe

    Study protocol: developing a decision system for inclusive housing: applying a systematic, mixed-method quasi-experimental design

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    Background Identifying the housing preferences of people with complex disabilities is a much needed, but under-developed area of practice and scholarship. Despite the recognition that housing is a social determinant of health and quality of life, there is an absence of empirical methodologies that can practically and systematically involve consumers in this complex service delivery and housing design market. A rigorous process for making effective and consistent development decisions is needed to ensure resources are used effectively and the needs of consumers with complex disability are properly met. Methods/Design This 3-year project aims to identify how the public and private housing market in Australia can better respond to the needs of people with complex disabilities whilst simultaneously achieving key corporate objectives. First, using the Customer Relationship Management framework, qualitative (Nominal Group Technique) and quantitative (Discrete Choice Experiment) methods will be used to quantify the housing preferences of consumers and their carers. A systematic mixed-method, quasi-experimental design will then be used to quantify the development priorities of other key stakeholders (e.g., architects, developers, Government housing services etc.) in relation to inclusive housing for people with complex disabilities. Stakeholders randomly assigned to Group 1 (experimental group) will participate in a series of focus groups employing Analytical Hierarchical Process (AHP) methodology. Stakeholders randomly assigned to Group 2 (control group) will participate in focus groups employing existing decision making processes to inclusive housing development (e.g., Risk, Opportunity, Cost, Benefit considerations). Using comparative stakeholder analysis, this research design will enable the AHP methodology (a proposed tool to guide inclusive housing development decisions) to be tested. Discussion It is anticipated that the findings of this study will enable stakeholders to incorporate consumer housing preferences into commercial decisions. Housing designers and developers will benefit from the creation of a parsimonious set of consumer-led housing preferences by which to make informed investments in future housing and contribute to future housing policy. The research design has not been applied in the Australian research context or elsewhere, and will provide a much needed blueprint for market investment to develop viable, consumer directed inclusive housing options for people with complex disability

    Regulation of hepatic glucose production and AMPK by AICAR but not by metformin depends on drug uptake through the equilibrative nucleoside transporter 1 (ENT1)

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    This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.Aim: Recently we have observed differences in the ability of metformin and AICAR to repress glucose production from hepatocytes using 8CPT-cAMP. Previous results indicate that besides activating protein kinase A, 8CPT-modified cAMP analogues suppress the Nitrobenzylthioinosine (NBMPR)-sensitive equilibrative nucleoside transporter ENT1. We aimed to exploit 8CPT-cAMP, 8CPT-2-Methyl-O-cAMP and NBMPR, which is highly selective for a high-affinity binding-site on ENT1, to investigate the role of ENT1 in the liver specific glucose lowering properties of AICAR and metformin. Methods: Primary mouse hepatocytes were incubated with AICAR and metformin in combination with cAMP analogues, glucagon, forskolin and NBMPR. Hepatocyte glucose production (HGP), and AMPK signalling were measured and a uridine uptake assay with supporting LC-MS was used to investigate nucleoside depletion from medium by cells. Results: AICAR and metformin increased AMPK pathway phosphorylation and decreased HGP induced by dibutyryl cAMP and glucagon. HGP was also induced by 8CPT-cAMP, 8CPT-2-Methyl-O-cAMP and NBMPR; however, in each case this was resistant to suppression by AICAR but not metformin. Cross-validation of tracer and mass spectrometry studies indicates that 8CPT-cAMP, 8CPT-2-Methyl-O-cAMP and NBMPR inhibited the effects of AICAR at least in part by impeding its uptake into hepatocytes. Conclusions: We report for the first time that suppression of ENT1 induces HGP. ENT1 inhibition also impedes uptake and effects of AICAR but not metformin on HGP. Further investigation of nucleoside transport may illuminate a better understanding of how metformin and AICAR each regulate HGP.L.L. was supported by a Cunningham Trust PhD studentship awarded to G.R. and C.B. G.R. acknowledges additional support from the MRC (MR/K012924/1). This work was part-funded by a Tenovus Scotland grant to C.B, who is a recipient of a Diabetes UK RD Lawrence Fellowship (13/0004647)
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