212 research outputs found
UV-B perceived by the UVR8 photoreceptor inhibits plant thermomorphogenesis
Small increases in ambient temperature can elicit striking effects on plant architecture, collectively termed thermomorphogenesis [1]. In Arabidopsis thaliana, these include marked stem elongation and leaf elevation, responses that have been predicted to enhance leaf cooling [ 2, 3, 4 and 5]. Thermomorphogenesis requires increased auxin biosynthesis, mediated by the bHLH transcription factor PHYTOCHROME-INTERACTING FACTOR 4 (PIF4) [ 6, 7 and 8], and enhanced stability of the auxin co-receptor TIR1, involving HEAT SHOCK PROTEIN 90 (HSP90) [9]. High-temperature-mediated hypocotyl elongation additionally involves localized changes in auxin metabolism, mediated by the indole-3-acetic acid (IAA)-amido synthetase Gretchen Hagen 3 (GH3).17 [10]. Here we show that ultraviolet-B light (UV-B) perceived by the photoreceptor UV RESISTANCE LOCUS 8 (UVR8) [11] strongly attenuates thermomorphogenesis via multiple mechanisms inhibiting PIF4 activity. Suppression of thermomorphogenesis involves UVR8 and CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1)-mediated repression of PIF4 transcript accumulation, reducing PIF4 abundance. UV-B also stabilizes the bHLH protein LONG HYPOCOTYL IN FAR RED (HFR1), which can bind to and inhibit PIF4 function. Collectively, our results demonstrate complex crosstalk between UV-B and high-temperature signaling. As plants grown in sunlight would most likely experience concomitant elevations in UV-B and ambient temperature, elucidating how these pathways are integrated is of key importance to the understanding of plant development in natural environments
Sources of Airborne Endotoxins in Ambient Air and Exposure of Nearby CommunitiesâA Review
Endotoxin is a bioaerosol component that is known to cause respiratory effects in exposed populations. To date, most research focused on occupational exposure, whilst much less is known about the impact of emissions from industrial operations on downwind endotoxin concentrations. A review of the literature was undertaken, identifying studies that reported endotoxin concentrations in both ambient environments and around sources with high endotoxin emissions. Ambient endotoxin concentrations in both rural and urban areas are generally below 10 endotoxin units (EU) mâ3; however, around significant sources such as compost facilities, farms, and wastewater treatment plants, endotoxin concentrations regularly exceeded 100 EU mâ3. However, this is affected by a range of factors including sampling approach, equipment, and duration. Reported downwind measurements of endotoxin demonstrate that endotoxin concentrations can remain above upwind concentrations. The evaluation of reported data is complicated due to a wide range of different parameters including sampling approaches, temperature, and site activity, demonstrating the need for a standardised methodology and improved guidance. Thorough characterisation of ambient endotoxin levels and modelling of endotoxin from pollution sources is needed to help inform future policy and support a robust health-based risk assessment process
A Controlled Study on the Characterisation of Bioaerosols Emissions from Compost
Bioaerosol emissions arising from biowaste treatment are an issue of public concern. To better characterise the bioaerosols, and to assess a range of measurement methods, we aerosolised green waste compost under controlled conditions. Viable and non-viable Andersen samplers, cyclone samplers and a real time bioaerosol detection system (Spectral Intensity Bioaerosol Sensor (SIBS)) were deployed simultaneously. The number-weighted fraction of fluorescent particles was in the range 22â26% of all particles for low and high emission scenarios. Overall fluorescence spectral profiles seen by the SIBS exhibited several peaks across the 16 wavelength bands from 298 to 735 nm. The size-fractionated endotoxin profile showed most endotoxin resided in the 2.1â9 ÎŒm aerodynamic diameter fraction, though up to 27% was found in a finer size fraction. A range of microorganisms were detected through culture, Matrix Assisted Laser Desorption and Ionisation Time of Flight Mass Spectrometry (MALDI-TOF) and quantitative polymerase chain reaction (qPCR), including Legionella pneumophila serogroup 1. These findings contribute to our knowledge of the physico-chemical and biological characteristics of bioaerosols from composting sites, as well as informing future monitoring approaches and data interpretation for bioaerosol measurement
Nutramara - Marine Functional Foods Research Initiative (MFFRI/07/01)
Final report of projectThe NutraMara â Marine Functional Foods Research Initiative was conceived by Sea Change - A Marine Knowledge, Research and Innovation Strategy for Ireland 2007-2013. The goal was to develop a collaborative funding mechanism that would create new research capacity and build the capabilities required to maximise the potential of Irelandâs extensive marine bioresources. By supporting a strong interdisciplinary research team, capable of exploring marine animals and plants as a sustainable source of materials for use as functional ingredients and foods, the vision for NutraMara was to position Ireland to the fore in use of marine bioresources as health beneficial ingredients. Commencing in 2008 and supported by funds of âŹ5.2 million from the Marine Institute and the Department of Agriculture, Food and the Marine, the research programme was led by Teagasc as the head of a multi-institutional consortium. The NutraMara consortium comprises marine bioresources and bioscience expertise, with food science and technology expertise from University College Cork; University College Dublin; the National University of Ireland Galway; the University of Limerick and Ulster University. Research effort was directed towards exploring Irelandâs marine bioresources â including macro- and microalgae, finfish and shellfish from wild and cultured sources: and discards from processing fish as sources of novel ingredients with bioactive characteristics. This discovery activity involved the collection of over 600 samples from 39 species of algae and fish and the analysis of 5,800 extracts, which resulted in 3,000 positive âhitsâ for bioactivity. The NutraMara consortium has built a strong research capacity to identify, characterise and evaluate marine-origin bioactives for use as/in functional foods. It further built the capacity to develop model foods enhanced with these marine-origin functional ingredients; providing insights to the processing challenges associated with producing functional ingredients from marine organisms. The consortium was actively engaged in research activities designed to identify and assess bioactive compounds from available marine resources, including polyphenols, proteins/peptides, amino acids, polysaccharides, polyunsaturated fatty acids and materials with antioxidant, probiotic or prebiotic properties. A key component of NutraMaraâs activities was the development of human capital. The recruitment of M.Sc. and PhD students and their integration within a dynamic research environment that has strong links to industry, provided lasting expertise and capabilities, which are relevant to the needs of Irelandâs food and marine sectors. NutraMara research led to the awarding of eighteen PhDs and recruitment of 21 post-doctoral researchers over the eight year research programme. In excess of 80 peer reviewed publications resulted from this research and more publications are planned. A further 100 posters and conference presentations were also delivered by NutraMara researchers and Principal Investigators. The development and implementation of training and exchange programmes aimed at providing early stage researchers with inter-disciplinary skills that are critical to their development as researchers, enhanced the research capacity of institutions, the industry sectors and the country as a whole. Principal Investigators involved in leading the NutraMara research programme have secured additional research grants of almost âŹ6 million from national and international sources and are engaged in extensive research collaboration involving marine and food research expertise; an activity which did not exist prior to NutraMara. The dissemination of knowledge and transfer of research results to industry were key activities in the research programme. The research outputs and visibility of NutraMara activity nationally resulted in 10 companies engaging in research and development activity with the consortium. Regular workshops and conferences organised by NutraMara attracted close to five hundred participants from Ireland and overseas. Members of the NutraMara core PI group have contributed to the formulation of new national foods and marine research policy and national research agenda, both during the national prioritisation exercise and in sectoral research strategies. This final project report describes the process by which research targets were identified, and the results of extensive screening and evaluation of compounds extracted from marine bioresources. It also highlights the development of new protocols designed to extract compounds in ways that are food friendly. Evaluating the functional properties, bioactivity and bioavailability of high potential marine compounds involved in vitro and in vivo testing. Pilot animal and human intervention studies yielded further insight to the potential and challenges in developing marine functional ingredients. As a result of work completed within the NutraMara consortium, Ireland is well positioned to continue to contribute to the development of ingredients derived from marine organisms and in doing so support the on-going development of Irelandâs food sector.Marine Institut
Creep deformation mechanisms in a Îł titanium aluminide
Titanium aluminides (TiAl) are considered as potential alternatives to replace nickel-based alloys of greater density for selected components within future gas turbine aero-engines. This is attributed to the high specific strength as well as the good oxidation resistance at elevated temperatures. The gamma (γ) titanium aluminide system Ti-45Al-2Mn-2Nb has previously demonstrated promising performance in terms of its physical and mechanical properties. The main aim of the current study, which is a continuation of a previously published paper, aims at evaluating the performance of this titanium aluminide system under high temperature creep conditions. Of particular interest, the paper is strongly demonstrating the precise capability of the Wilshire Equations technique in predicting the long-term creep behaviour of this alloy. Moreover, it presents a physically meaningful understanding of the various creep mechanisms expected under various testing conditions. To achieve this, two creep specimens, tested under distinctly different stress levels at 700 °C have been extensively examined. Detailed microstructural investigations and supporting transmission electron microscopy (TEM) have explored the differences in creep mechanisms active under the two stress regimes, with the deformation mechanisms correlated to Wilshire creep life prediction curves
Protocols for an Aboriginal-led, Multi-methods Study of the Role of Aboriginal and Torres Strait Islander Health Workers, Practitioners and Liaison Officers in Quality Acute Health Care
ObjectivesAboriginal and Torres Strait Islander Health Workers/Practitioners and Liaison Officers play an important, often critical role providing advocacy and cultural and emotional support for Aboriginal and Torres Strait Islander patients. The main goals of this research are to explore i) how Aboriginal and Torres Strait Islander Health Workers/Practitioners and Liaison Officers are integrated in the routine delivery of care for Aboriginal and Torres Strait Islander peoples in hospital, and ii) how the role of Aboriginal and Torres Strait Islander Health Workers/Practitioners and Liaison Officers facilitates quality health outcomes.
MethodsThis study is being conducted in three different hospitals using a multi-method approach including: yarning and Dadirri, patient journey mapping, survey and semi-structured interviews. Ethics approval has been provided from four ethics committees covering the three project sites in Australia (Adelaide, South Australia; Sydney, New South Wales and Alice Springs, Northern Territory).
SignificanceThis study uses innovative methodology founded on the privileging of Aboriginal and Torres Strait Islander knowledges to collect Aboriginal and Torres Strait Islander perspectives and understand patient journeys within acute health care systems. This project is led by Aboriginal and Torres Strait Islander researchers and guided by the Project Steering Committee comprised of stakeholders.
ImplicationsThere is limited research that explores quality acute care processes and the integration of Aboriginal and Torres Strait Islander Health Workers/Practitioners work within health care teams. This research will make a valuable contribution to understanding how hospital services can achieve quality acute health care experiences for Aboriginal and Torres Strait Islander People
Scoping studies to establish the capability and utility of a real-time bioaerosol sensor to characterise emissions from environmental sources
A novel dual excitation wavelength based bioaerosol sensor with multiple fluorescence bands called Spectral Intensity Bioaerosol Sensor (SIBS) has been assessed across five contrasting outdoor environments. The mean concentrations of total and fluorescent particles across the sites were highly variable being the highest at the agricultural farm (2.6âŻcmâ3 and 0.48âŻcmâ3, respectively) and the composting site (2.32âŻcmâ3 and 0.46âŻcmâ3, respectively) and the lowest at the dairy farm (1.03âŻcmâ3 and 0.24âŻcmâ3, respectively) and the sewage treatment works (1.03âŻcmâ3 and 0.25âŻcmâ3, respectively). In contrast, the number-weighted fluorescent fraction was lowest at the agricultural site (0.18) in comparison to the other sites indicating high variability in nature and magnitude of emissions from environmental sources. The fluorescence emissions data demonstrated that the spectra at different sites were multimodal with intensity differences largely at wavelengths located in secondary emission peaks for λex 280 and λex 370. This finding suggests differences in the molecular composition of emissions at these sites which can help to identify distinct fluorescence signature of different environmental sources. Overall this study demonstrated that SIBS provides additional spectral information compared to existing instruments and capability to resolve spectrally integrated signals from relevant biological fluorophores could improve selectivity and thus enhance discrimination and classification strategies for real-time characterisation of bioaerosols from environmental sources. However, detailed lab-based measurements in conjunction with real-world studies and improved numerical methods are required to optimise and validate these highly resolved spectral signatures with respect to the diverse atmospherically relevant biological fluorophores
A U-Shape Fibre-Optic pH Sensor Based on Hydrogen Bonding of Ethyl Cellulose with a Sol-Gel Matrix
© 1983-2012 IEEE. Development of a biocompatible pH sensor is of importance in biomedical applications, particularly for in vivo measurement, providing necessary information for clinical diagnosis and treatment such as chronic wounds and foetal acidosis. Traditional pH-indicator based optical sensors have problems of dye-leaching and photobleaching that restrict their uses in long-term monitoring. In this work, a dye-free fibre optic pH sensor is proposed consisting of a U-shape multimode optical fibre coated with a hybrid organic-inorganic composite film. The film is formed by cross-linking ethyl cellulose with a silica matrix at an optimised ethyl cellulose/silica molar ratio of 0.0065 via weakly interacted hydrogen bonding. This bonding is affected by hydrogen concentration (i.e., pH) in a solution resulting in a morphological change of the polymer aggregation presented in the silica matrix leading to refractive index change of the film. The developed sensor shows a reversible response to pH from 4.5 to 12.5 and exhibits linear correlation between transmitted light power and pH with a limit of agreement (LoA) between the sensor and a commercial probe of ±0.2 pH. For a clinically important range of pH values between 6 and 8 the LoA is ±0.1 pH. The sensor has low cross-sensitivity to temperature as the maximum interpreted pH change attributed to the power change is 0.12 pH when the temperature changes from 21 °C to 39 °C. To demonstrate biomedical relevance, the sensor is used to monitor pH of human serum. An in-house cytotoxicity assay is conducted with mouse fibroblast cell revealing that the film is not cytotoxic
Predicting the loss of forests, carbon stocks and biodiversity driven by a neotropical âgold rushâ
The loss of tropical forests represents a major threat to biodiversity. With accelerating deforestation in large parts of the Amazon, the Guiana Shield region, with its large expanse of closed forest cover, has the potential to play a crucial role in both climate change mitigation and biodiversity conservation. However, the region is now facing increasing deforestation pressures, primarily from artisanal gold mining activities concentrated in the nation of Guyana. To identify areas of Guyana at the highest risk of deforestation over the next 25 years, we employed a spatio-temporal modelling approach that accounted for the stochastic and contagious nature of deforestation. Our model predicted a 9 % net decrease in total forest cover by 2043. While the primary drivers of deforestation were mining and human settlements, protected areas were shown to reduce the probability of deforestation. Therefore, we assessed the potential impact of a proposed expansion of the protected area network in Guyana, on forest loss, carbon stocks and habitat loss for the country's most threatened forest vertebrates. Establishing the proposed protected areas would reduce forest loss by 17 %, predicted habitat losses by an average of 1.9 % per vertebrate group, and aboveground carbon emissions by 466,968 t over the next 25 years. These findings highlight the utility of using predictive models to identify areas at risk of future deforestation, which can contribute to the development of effective strategies against tropical forest loss, biodiversity loss and climate change
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