Numerical investigation of laminar flow in micro-tubes with designed surface roughness

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.Recently, there has been a rapid growth in applications that deal with fluid flow at micro-scale where surface roughness is a real feature in these applications. Published literature shows conflicting findings regarding the effect of surface roughness on the friction factor of laminar flow at micro-scale. The understanding of fluid flow behavior in micro-tubes is very important for effective design of micro-fluidic devices. This work presents a numerical investigation of the effect of various surface roughness geometries on friction factor in fluid flow in the laminar regime. Results indicate that surface roughness causes deviation of the frictional factor from conventional theory with various values depending on the height and shape of the roughness used

Electrophoretic manipulation of multiple-emulsion droplets

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.In this report the electrophoretic manipulation of structured oil-water-oil (O/W)/O core-shell droplets is presented. Water shells have been created that allow the electrophoretic manipulation of oil droplets in an oil environment. It was found that the inner droplet regardless of size and composition does not affect the electrophoretic mobility of the outer water shell, neither before nor after contact with a biased electrode. This method can be used for the manipulation of oil droplets in a continuous oil phase or for the transportation of microbial cells that would otherwise be killed at low electric field strengths

Adrenal Incidentaloma Diagnosed as a Pheochromocytoma in a fifteen-year-old Dog - An Unexpected Finding with Deadly Consequences

Adrenal incidentalomas are masses of the adrenal gland discovered inadvertently during diagnostic procedures, from which a significant percentage are pheochromocytomas and these tumors are rare. Here we report a case of a 15-year-old male dog whose main complaints were a soft cervical mass and mild generalized weakness. Blood cell count, routine biochemistry, arterial blood pressure and electrocardiogram were performed. Diagnostic imaging revealed a 3.5 cm mass next to the right adrenal gland. Surgery was performed and histopathology examination of the mass confirmed a malignant pheochromocytoma. The dog died 96 hours later after surgery. At necropsy, metastasis was found in cervical lymph node. Considering vague and episodic clinical signs, pheochromocytoma antemortem diagnosis is uncommon. The main aim of this case is to highlight this endocrinology disorder, increasing the awareness of clinicians to this difficult diagnostic condition

Numerical investigation of laminar flow heat transfer through helically coiled tubes using Al2O3 nanofluid

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.Nanofluids have been reported to enhance heat transfer performance in heat exchangers. Additionally, the use of helical coils has shown to be another passive heat transfer enhancement technique. This work presents a CFD modeling study to investigate the laminar heat transfer through helical tubes with nanofluids. The developed CFD models were validated against published experimental results and empirical correlations in the literature. The effects of particles concentration and Reynolds number on heat transfer coefficient were numerically investigated. Results have shown that Al2O3 dispersed in water increases the heat transfer coefficient in helical coils by up to 4.5 times that of pure water in straight tubes at same Reynolds number. For concentrations larger than 2%, Al2O3 is more suitable for thermal systems of small thermal loads where the pumping power is not critical

Mobility and Maternal Position during Childbirth in Tanzania: An Exploratory Study at Four Government Hospitals.

Emerging research evidence suggests a potential benefit in being upright in the first stage of labour and a systematic review of trials suggests both benefits and harmful effects associated with being upright in the second stage of labour. Implementing evidence-based obstetric care in African countries with scarce resources is particularly challenging, and requires an understanding of the cumulative nature of science and commitment to applying the most up to date evidence to clinical decisions. In this study, we documented current practice rates, explored the barriers and opportunities to implementing these procedures from the provider perspective, and documented women's preferences and satisfaction with care. This was an exploratory study using quantitative and qualitative methods. Practice rates were determined by exit interviews with a consecutive sample of postnatal women. Provider views were explored using semi-structured interviews (with doctors and traditional birth attendants) and focus group discussions (with midwives). The study was conducted at four government hospitals, two in Dar es Salaam and two in the neighbouring Coast region, Tanzania. MAIN OUTCOME MEASURES: Practice rates for mobility during labour and delivery position; women's experiences, preferences and views about the care provided; and provider views of current practice and barriers and opportunities to evidence-based obstetric practice. Across all study sites more women were mobile at home (15.0%) than in the labour ward (2.9%), but movement was quite restricted at home before women were admitted to labour ward (51.6% chose to rest with little movement). Supine position for delivery was used routinely at all four hospitals; this was consistent with women's preferred choice of position, although very few women are aware of other positions. Qualitative findings suggest obstetricians and midwives favoured confining to bed during the first stage of labour, and supine position for delivery. The barriers to change appear to be complicated and require providers to want to change, and women to be informed of alternative positions during the first stage of labour and delivery. We believe that highlighting the gap between actual practice and current evidence provides a platform for dialogue with providers to evaluate the threats and opportunities for changing practice

A dose-dependent plasma signature of the safety and immunogenicity of the rVSV-Ebola vaccine in Europe and Africa.

The 2014-2015 Ebola epidemic affected several African countries, claiming more than 11,000 lives and leaving thousands with ongoing sequelae. Safe and effective vaccines could prevent or limit future outbreaks. The recombinant vesicular stomatitis virus-vectored Zaire Ebola (rVSV-ZEBOV) vaccine has shown marked immunogenicity and efficacy in humans but is reactogenic at higher doses. To understand its effects, we examined plasma samples from 115 healthy volunteers from Geneva who received low-dose (LD) or high-dose (HD) vaccine or placebo. Fifteen plasma chemokines/cytokines were assessed at baseline and on days 1, 2 to 3, and 7 after injection. Significant increases in monocyte-mediated MCP-1/CCL2, MIP-1β/CCL4, IL-6, TNF-α, IL-1Ra, and IL-10 occurred on day 1. A signature explaining 68% of cytokine/chemokine vaccine-response variability was identified. Its score was higher in HD versus LD vaccinees and was associated positively with vaccine viremia and negatively with cytopenia. It was higher in vaccinees with injection-site pain, fever, myalgia, chills, and headache; higher scores reflected increasing severity. In contrast, HD vaccinees who subsequently developed arthritis had lower day 1 scores than other HD vaccinees. Vaccine dose did not influence the signature despite its influence on specific outcomes. The Geneva-derived signature associated strongly (ρ = 0.97) with that of a cohort of 75 vaccinees from a parallel trial in Lambaréné, Gabon. Its score in Geneva HD vaccinees with subsequent arthritis was significantly lower than that in Lambaréné HD vaccinees, none of whom experienced arthritis. This signature, which reveals monocytes' critical role in rVSV-ZEBOV immunogenicity and safety across doses and continents, should prove useful in assessments of other vaccines

Standardizing and Scaling up Quality Adolescent Friendly Health Services in Tanzania.

Adolescents in Tanzania require health services that respond to their sexual and reproductive health - and other - needs and are delivered in a friendly and nonjudgemental manner. Systematizing and expanding the reach of quality adolescent friendly health service provision is part of the Tanzanian Ministry of Health and Social Welfare's (MOHSW) multi-component strategy to promote and safeguard the health of adolescents. We set out to identify the progress made by the MOHSW in achieving the objective it had set in its National Adolescent Health and Development Strategy: 2002-2006, to systematize and extend the reach of Adolescent Friendly Health Services (AFHS) in the country. We reviewed plans and reports from the MOHSW and journal articles on AFHS. This was supplemented with several of the authors' experiences of working to make health services in Tanzania adolescent friendly. The MOHSW identified four key problems with what was being done to make health services adolescent friendly in the country - firstly, it was not fully aware of the various efforts under way; secondly, there was no standardized definition of AFHS; thirdly, it had received reports that the quality of the AFHS being provided by some organizations was poor; and fourthly, only small numbers of adolescents were being reached by the efforts that were under way. The MOHSW responded to these problems by mapping existing services, developing a standardized definition of AFHS, charting out what needed to be done to improve their quality and expand their coverage, and integrating AFHS within wider policy and strategy documents and programmatic measurement instruments. It has also taken important preparatory steps to stimulate and support implementation. The MOHSW is aware that the focus of the effort must now shift from the national to the regional, council and local levels. The onus is on regional and council health management teams as well as health facility managers to take the steps needed to ensure that all adolescents in the country obtain the sexual and reproductive health (SRH) services they need, delivered in a friendly and non-judgemental manner. But they cannot do this without substantial and ongoing support

Observations on Rehabilitation of Traumatic Paraplegia using Body Weight Support Training and Functional Electrical Stimulation

Walking is the unthinking transportation of daily life, supporting countless but essential trips within home and beyond, walking holds profound symbolic importance. When a person sustains spinal cord injury the most obvious functional limitation encountered is loss of ambulation. Conventional rehabilitation primarily provides compensatory strategy for accomplishing mobility and strengthening above the level of lesion. Recently new approach to facilitate locomotor recovery and bladder and bowel emptying have been explored,these include:-1) Body weight support walking (BWS), 2) Functional Electrical Stimulation (FES) and 3) Interferential Therapy (IFT) To determine whether BWS training, FES and IFT have potential to improve walking function and bladder emptying in individuals with SCI, 20 subjects with spinal cord injury at the level of dorsolumber and lumbosacral regions were studied. Significant improvement in the muscle power of lower limbs and bladder control was seen in patients who received FES and IFT after the injury and at follow up of 6 months. Body support walking proved to be effective in early rehabilitation of patients with SCI. Hence comprehensive management with these gadgets provided early ambulation, bladder and bowel training and overall rehabilitation of patients. Such patients can be made independent for their ADL within the home with orthotic devices, wheel chair etc

Physics in Riemann's mathematical papers

Riemann's mathematical papers contain many ideas that arise from physics, and some of them are motivated by problems from physics. In fact, it is not easy to separate Riemann's ideas in mathematics from those in physics. Furthermore, Riemann's philosophical ideas are often in the background of his work on science. The aim of this chapter is to give an overview of Riemann's mathematical results based on physical reasoning or motivated by physics. We also elaborate on the relation with philosophy. While we discuss some of Riemann's philosophical points of view, we review some ideas on the same subjects emitted by Riemann's predecessors, and in particular Greek philosophers, mainly the pre-socratics and Aristotle. The final version of this paper will appear in the book: From Riemann to differential geometry and relativity (L. Ji, A. Papadopoulos and S. Yamada, ed.) Berlin: Springer, 2017

Overdiagnosis in breast cancer screening: the importance of length of observation period and lead time

PMCID: PMC3706885This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited