1,697 research outputs found
The Use of Functional Traits to Identify Grasses and Fodder Shrubs for Domestication to Suit a Changing Climate
There is uncertainty about future climatic predictions; however there is little doubt amongst experts that the future will be warmer. Climate change and the associated elevation in atmospheric CO2 level and temperatures will provide novel challenges and potential opportunities for cultivated plant species. Plant breeding and domestication can contributed to improvements in both yield and quality of grasses and fodder shrubs. A range of key functional traits is required to cope with this changing climate. The main challenges that are discussed are new pests and pathogens; changes in the pattern of nutrient supply and forage quality; challenge associated with a shorter growing season; drought tolerance and persistence. With the domestication of any species, consideration needs to be given in terms of duty of care (weediness, anti-nutritional/toxic to animals, regulations) and the on farm adoption of new selections. Two case studies have been included in the paper, one on native grasses and the other on native shrub, old man saltbush
PHP1 Incorporating the Patient's Voice Into the Assessment of Medical Devices: A Comparison of the United States and Europe
A novel dielectric tensiometer enabling precision PID-based irrigation control of polytunnel-grown strawberries in coir
The benefits of closed-loop irrigation control have been demonstrated in grower trials which show the potential for improved crop yields and resource usage. Managing water use, by controlling irrigation in response to soil or substrate moisture changes, to meet crop water demands is a popular approach but requires substrate specific moisture sensor calibrations and knowledge of the moisture levels that result in water deficit or overwatering. The use of water tension sensors removes the need for substrate specific calibration and enables a more direct relationship with hydraulic conductivity. In this paper, we present a novel dielectric tensiometer that has been designed specifically for use in soil-free substrates such as coir, peat and Rockwool with a water tension measurement range of 0.7 kPa to 2.5 kPa. This new sensor design has also been integrated with a precision PID-based (drip) irrigation controller in a small-scale coir substrate strawberry growing trial: 32 strawberry plants in 4 coir growbags under a polytunnel. The data illustrates that excellent regulation of water tension in coir can be achieved which delivers robust and
precise irrigation control - matching water delivery to the demands of the plants. During a 30-day growing period vapour pressure deficit (VPD) and daily water use data was collected and the irrigation controller set to maintain coir water tension at the following levels: 0.90 kPa, 0.95 kPa and 1 kPa for at least 7 consecutive days at each level. For each setpoint the coir water tension was maintained by the irrigation controller to within ±0.05 kPa. Meanwhile the polytunnel VPD varied diurnally from 0 to a maximum of 5 kPa over the trial period. Furthermore, the combination of the dielectric tensiometer and the method of PID-based irrigation control resulted in a linear relationship between daily average VPD and daily water use over 10 days during the cropping period
Understanding in situ ozone production in the summertime through radical observations and modelling studies during the Clean air for London project (ClearfLo)
Measurements of OH, HO2, RO2i (alkene and aromatic-related RO2) and total RO2 radicals taken during the ClearfLo campaign in central London in the summer of 2012 are presented. A photostationary steady-state calculation of OH which considered measured OH reactivity as the OH sink term and the measured OH sources (of which HO2+ NO reaction and HONO photolysis dominated) compared well with the observed levels of OH. Comparison with calculations from a detailed box model utilising the Master Chemical Mechanism v3.2, however, highlighted a substantial discrepancy between radical observations under lower NOx conditions ([NO] 3 ppbv) the box model increasingly underpredicted total [RO2]. The modelled and observed HO2 were in agreement, however, under elevated NO concentrations ranging from 7 to 15 ppbv. The model uncertainty under low NO conditions leads to more ozone production predicted using modelled peroxy radical concentrations ( ≈ 3 ppbv h-1) versus ozone production from peroxy radicals measured ( ≈ 1 ppbv h-1). Conversely, ozone production derived from the predicted peroxy radicals is up to an order of magnitude lower than from the observed peroxy radicals as [NO] increases beyond 7 ppbv due to the model underprediction of RO2 under these conditions
Cognitive Test Scores and Progressive Cognitive Decline in the Aberdeen 1921 and 1936 Birth Cohorts
Acknowledgments: We remain grateful to the kindness of the staff at the Scottish Council for Research in Education who allowed us access to their archive and remained supportive and gracious throughout our collaboration. We thank the many people of Aberdeen who volunteered generously and committed to the long-term success of this program. We thank Victoria Bourne, who made substantial contributions to study design, data collection, data analysis and hypothesis generation. Jen Herbert (deceased) recruited the ABC36 participants, collected data (sessions I and II) and, through her encouragement and professionalism, ensured the continued involvement of many participants. She was much loved by participants and the study team. Funding: The Aberdeen Birth Cohort 1921 and 1936 research program was established in 1997 with funding from the Henry Smith (Kensington Estates) Charity and continued by The UK Biotechnology and Biological Sciences Research Council (1999–2002), The Wellcome Trust (2001–2006), The Scottish Government (2000–2002), the Medical Research Council (2003), Alzheimer Research UK (2002–2005) and the University of Aberdeen Development Trust (2007–2010, 2014).Peer reviewedPublisher PD
Preference for different relaxation techniques by COPD patients: comparison between six techniques.
BACKGROUND: A review of the effectiveness of relaxation techniques for chronic obstructive pulmonary disease patients has shown inconsistent results, but studies have varied in terms of technique and outcome measures. AIM: To determine patient preference for different relaxation techniques. METHODS: Chronic obstructive pulmonary disease patients were presented with six techniques via a DVD and asked to rate the techniques in terms of effectiveness, rank in order of likely use, and comment. RESULTS: Patients differed in the technique preferred and reason for that preference, but the most commonly preferred technique both for effectiveness and ease of use was "thinking of a nice place" followed by progressive relaxation and counting. Familiarity and ease of activity were commonly given reasons for preference. CONCLUSION: Rather than providing patients with a single technique that they might find difficult to implement, these results suggest that it would be better to give a choice. "Thinking of a nice place" is a popular but under-investigated technique
Electrical method of monitoring percolation and abrasion of conducting spheres due to shear flow of a dense suspension in a narrow gap
The following article appeared in (MANNAN, S.H., HUTT, D.A.and WHALLEY, D.C., 1999. Electrical method of monitoring percolation and abrasion of conducting spheres due to shear flow of a dense suspension in a narrow gap. Applied Physics Letters, 75(6), pp. 871-2) and may be found at http://link.aip.org/link/?APPLAB/75/871/1This letter describes a method for studying the behavior of rigid particles in a dense suspension
when they are forced into contact during flow within a narrow gap. The particles form transient
percolating networks spanning the boundary walls, and will be crushed together. The method
involves measuring the dc electrical resistance across the gap. The suspension e.g., solder paste
consists of electrically conducting particles suspended in an insulating fluid. The electrical
resistance drops when the particles are in contact with each other and the walls, and the insulating
films on the surface of the conductors have been broken through. The results show a dramatic
change in behavior as the ratio of gap to particle diameter is varied
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