1,280 research outputs found

    Alternative use of grassland biomass for biorefinery in Ireland: a scoping study

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    The need to reduce greenhouse gas emissions and dependency on fossil fuels has been one of the main driving forces to use renewable resources for energy and chemicals. The integrated use of grassland biomass for the production of chemicals and energy, also known as Green Biorefinery (GBR), has received much attention and several European countries have developed GBR systems, including Austria, Denmark and Germany. In Ireland, approximately 90% of the 4.3 million hectares used for agriculture is under grassland and used in livestock production systems. Recently livestock numbers have declined and a surplus of grass biomass is predicted. GBR has potential to provide supplementary income from this surplus grass. As part of a scoping study, I assessed the economic, technical and environmental feasibility of a GBR in an Irish context, and developed a blueprint for a first generation GBR. Scenario analyses suggested that the ideal catchment area for a GBR was 700-800 ha depending on biomass availability within the catchment area, and the availability should be in excess of 30% in order to contain transport costs. An added benefit of a decentralised GBR facility processing approx. 0.8 t of dry matter per hour is that it allows for ease of operation, and better knowledge of the source and quality of the herbage being supplied. The viability of a GBR will be highest in areas which experience declining numbers of livestock and lower farm income, particularly. This mainly, but not exclusively, occurs in areas with many beef farms. These areas have a high potential availability of surplus grass biomass and in such a situation the GBR would not have to compete with traditional agricultural commodities, but rather would provide potential supplementary income to farmers. The transitional development of a GBR system is likely to be most successful if current harvesting practices (i.e. a two-cut silage system) are adopted. The quality of the biomass from such a harvesting system is compatible with the basic GBR technologies used to produce insulation materials and proteinaceous products for animal feed. In the longer-term, higher value products could be produced by retro-fitting the GBR facility. Analyses also showed that feedstock quality can be best controlled by operating a silage-only system, with on-site ensiling of the grass material at the GBR facility. The use of silage as a feedstock also facilitates year-round operation of the GBR facility. Biorefinery processes are energy intensive. Therefore, the viability of the GBR largely depends on self–sufficiency for energy. This can be achieved by anaerobic digestion of the fibre slurries that remain after processing. The residual material remaining after the anaerobic digestion can be used as fertiliser on the farm supplying the biomass, as part of a “waste management strategy” that aims to maintain nutrient balance between the GBR and the source farms. This recycling will reduce direct costs of the supplying farms. The blueprint outlined in this thesis provides a framework for the development of a first generation GBR. The blueprint has also identified key areas that require further research: improved ensiling techniques, integration of livestock farming systems and GBR systems, and nutrient budgeting of the GBR system. <br/

    The production, harvest and adsorptive recovery of an infectious herpes simplex virus vaccine

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    At present there is not a reliable vaccine against herpes virus. Viral protein vaccines as yet have proved unsuccessful to meet the challenge of raising an appropriate immune response. Cantab Pharmaceuticals has produced a virus vaccine that can undergo one round of replication in the recipient in order to produce a more specific immune reaction. This virus is called Disabled Infectious Single Cycle Herpes Simplex Virus (DISC HSV) which has been derived by deleting the essential gH gene from a type 2 herpes virus. This vaccine has been proven to be effective in animal studies. Existing methods for the purification of viruses rely on laboratory techniques and for vaccine production would be on a far too small a scale. There is therefore a need for new virus purification methods to be developed in order to meet these large scale needs. An integrated process for the manufacture of a purified recombinant DISC HSV is described. The process involves culture of complementing Vero (CR2) cells, virus infection and manufacture, virus harvesting and subsequent downstream processing. The identification of suitable growth parameters for the complementing cell line and optimal limes for both infection and harvest are addressed. Various traditional harvest methods were investigated and found not to be suitable for a scaled up process. A method of harvesting, that exploits the elution of cell associated viruses by the competitive binding of exogenous heparin to virus envelope gC proteins, is described and is shown to yield significantly less contaminated process streams than sonication or osmotic approaches that involve cell rupture (with> 10-fold less complementing cell protein). High concentrations of salt (>0.8M NaCl) exhibit the same effect, although the high osmotic strength ruptures cells and increase the contamination of the process stream. This same heparin-gC protein affinity interaction is also shown to provide an efficient adsorptive purification procedure for herpes viruses which avoids the need to pre-treat the harvest material, apart from clarification, prior to chromatography. Subsequent column eluates provide product fractions with a 100-fold increase in virus titre and low levels of complementing cell protein and DNA (0.05 pg protein/pfu and 1.2 x 104 pg DNA/pfu respectively)

    Evaluation of a New Recombinant K39 Rapid Diagnostic Test for Sudanese Visceral Leishmaniasis.

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    A new rK39 rapid diagnostic dipstick test (DiaMed-IT-Leish) was compared with aspiration and a direct agglutination test (DAT) for diagnosis of visceral leishmaniasis (VL) in 201 parasitologically confirmed cases, 133 endemic controls, and in 356 clinical suspects in disease-endemic and -epidemic areas in Sudan. The sensitivity of the rK39 test in parasitologically confirmed VL cases was 90%, whereas the specificity in disease-endemic controls was 99%. The sensitivity of the DAT was 98%. In clinically suspected cases, the sensitivity of the rK39 test was 81% and the specificity was 97%. When compared with the diagnostic protocol based on the DAT and aspiration used by Médecins sans Frontières in epidemic situations, the positive predictive value was 98%, and the negative predictive value was 71%. This rK39 rapid diagnostic test is suitable for screening as well as diagnosis of VL. Further diagnostic work-up of dipstick-negative patients with clinically suspected VL is important. The ease and convenience of the dipstick test will allow decentralization and improved access to care in disease-endemic areas in Sudan

    Growing grass for a green biorefinery - an option for Ireland?

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    Growing grass for a green biorefinery – an option for Ireland? Mind the gap: deciphering the gap between good intentions and healthy eating behaviour Halting biodiversity loss by 2020 – implications for agriculture A milk processing sector model for Irelan

    Design implementation and evaluation of a tablet-based student response system for an engineering classroom

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    Student response systems (SRSs) have generated significant debate and discussion in the educational research literature in the past decade. It is well known that they offer several important advantages including encouraging student interaction, offering anonymous and instant student feedback and improving the student learning experience. While several different types of such systems exist, they nevertheless remain limited in their input capabilities. In particular, they typically only allow for multiple-choice style responses, although some devices do cater for numerical and textual input. However, most of the available SRSs do not allow for freeform input such as mathematical equations, graphical drawings or circuit diagrams. This is of particular relevance to Engineering and Science disciplines where such information is core to the student learning. The approach to solving a problem is often as important, if not more so, than the actual final answer itself. This paper presents a classroom response system that allows for freeform input and operates on any smart media device with a touch interface and that employs the Android operating system, such as everyday smart phones and tablets. The proposed system involves three different components, namely a student application that allows for sketch capabilities, a lecturer application that allows for the viewing and marking of multiple student sketches and a cloud service for the exchange of messages. In addition, this proposed system was evaluated by a class of engineering students at NUI Maynooth, the results of which are presented within

    The value of emergency medicine placements for postgraduate doctors: views of Foundation Year 2 doctors and training leads in the emergency department (ED)

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    Objectives: To examine the delivery of postgraduate training in the emergency medicine setting and its impact on postgraduate doctor (Foundation Year 2) performance and competence. Methods: A national study in four emergency departments (EDs) in England between 2009 and 2010 was undertaken. Semistructured interviews with ED training leads (TLs) and focus groups with Foundation Year 2 (F2) doctors were carried out in each ED. Interviews and focus group data were analysed to compare the perspectives of F2 doctors and TLs on the delivery of training and performance and confidence of F2 doctors. Results: Interviews were carried out with eight TLs and focus groups with 30 F2s. F2 doctors and EDTLs agreed that ED was a valuable environment for F2 doctors to develop their competence, with exposure to a broad range of patients and the opportunity to make decisions about clinical care. Diverging views existed around competence and performance of F2s. F2 doctors had anxieties about decision-making (particularly discharging patients) and required regular feedback to feel confident in their care. TLs recognised a need for more supervision and support for F2 doctors but this was challenging in a busy, performance-led service. Conclusions: Emergency medicine placements were important in the development of confident and competent F2 doctors, particularly in the context of less clinical exposure in other specialty placements. However, there are competing tensions between elements of postgraduate learning and service delivery within emergency medicine that require addressing to enable trainees to optimally develop knowledge and skills in this environment

    Combined visible and near-infrared OPA for wavelength scaling experiments in strong-field physics

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    We report the operation of an optical parametric amplifier (OPA) capable of producing gigawatt peak-power laser pulses with tunable wavelength in either the visible or near-infrared spectrum. The OPA has two distinct operation modes (i) generation of >350 uJ, sub 100 fs pulses, tunable between 1250 - 1550 nm; (ii) generation of >190 uJ, sub 150 fs pulses tunable between 490 - 530 nm. We have recorded high-order harmonic spectra over a wide range of driving wavelengths. This flexible source of femtosecond pulses presents a useful tool for exploring the wavelength-dependence of strong-field phenomena, in both the multi-photon and tunnel ionization regimes.Comment: 14 pages, 9 figures, This paper was published in Proceedings of SPIE 10088, Nonlinear Frequency Generation and Conversion: Materials and Devices XVI, doi 10.1117/12.225077

    Characterising non-urgent users of the emergency department (ED): A retrospective analysis of routine ED data

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    Background The pressures of patient demand on emergency departments (EDs) continue to be reported worldwide, with an associated negative impact on ED crowding and waiting times. It has also been reported that a proportion of attendances to EDs in different international systems could be managed in settings such as primary care. This study used routine ED data to define, measure and profile non-urgent ED attendances that were suitable for management in alternative, non-emergency settings. Methods We undertook a retrospective analysis of three years of Hospital Episode and Statistics Accident Emergency (HES A&E) data for one large region in England, United Kingdom (April 1st 2011 to March 31st 2014). Data was collected on all adult (>16 years) ED attendances from each of the 19 EDs in the region. A validated process based definition of nonurgent attendance was refined for this study and applied to the data. Using summary statistics non-urgent attenders were examined by variables hypothesised to influence them as follows: age at arrival, time of day and day of week and mode of arrival. Odds ratios were calculated to compare non-urgent attenders between groups. Results There were 3,667,601 first time attendances to EDs, of which 554,564 were defined as nonurgent (15.1%). Non-urgent attendances were significantly more likely to present out of hours than in hours (OR = 1.19, 95% CI: 1.18 to 1.20, P<0.001). The odds of a non-urgent attendance were significantly higher for younger patients (aged 16–44) compared to those aged 45–64 (odds ratio: 1.42, 95% CI: 1.41 to 1.43, P<0.001) and the over 65’s (odds ratio: 3.81, 95% CI: 3.78 to 3.85, P<0.001). Younger patients were significantly more likely to attend non-urgently out of hours compared to the 45–64’s (OR = 1.24, 95% CI: 1.22 to 1.25, P<0.001) and the 65+’s (OR = 1.38, 95% CI: 1.35 to 1.40, P<0.001). 110,605/554,564 (19.9%) of the non-urgent attendances arrived by ambulance, increasing significantly out of hours versus in hours (OR = 2.12, 95% CI: 2.09 to 2.15, P<0.001). Conclusions Younger adults are significantly more likely as older counterparts to use the ED to obtain healthcare that could be provided in a less urgent setting and also more likely to do this out of hours. Alternative services are required to manage non-urgent demand, currently being borne by the ED and the ambulance service, particularly in out of hours
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