329 research outputs found
Urea treatment affects safe rates of seed placed nitrogen in Saskatchewan
Non-Peer ReviewedPlacing urea in close proximity to seed can cause seedling damage resulting in poor crop establishment. Plant densities are often well below the optimum, and plants that do emerge can exhibit poor vigor. Several strategies have been developed to reduce risk of seed damage from urea. Restricting the amount that is seed placed, placing urea at a safe distance and placement before or after seeding are effective but may not allow for application of adequate N or increase equipment and operating costs. Recently treatments applied to the urea granule such as Agrotain and polymer coating have been developed to slow the conversion to ammonium. Research suggests that the safe rate of N can be increased by 50% where Agrotain is used and are less clear when polymer coatings are used. To demonstrate how Agrotain and polymer treated urea affect crop establishment and yield, rates of 0, 1, 1.5, 2 and 4 times the recommended safe rate were seed placed at Scott, Swift Current, Canora and Redvers, Saskatchewan. Trials were conducted with wheat at all locations, and canola at Scott. Seed placed untreated urea was used as a check. As well, an alternate option using seed placed untreated urea followed by liquid urea ammonium nitrate dribble banded 20 to 35 days after seeding was investigated. Impact of treatments on plant density varied with rainfall across locations. Sites with lower precipitation after seeding indicated more severe damage to seedlings. Untreated urea placed with the seed had the greatest impact on plant density but, Agrotain and polymer treatments also led to decreases at high N rates. The improvement of Agrotain over untreated urea generally confirmed manufacturer recommendations that safe rates of seed placed urea can be increased by about 50%. The polymer was very effective at reducing damage from seed placed urea, but still generally resulted in fewer plants than side band at 4 times the recommended rate of N. Grain yield responses were also variable across locations. At most sites where plant stand reductions were high yield was also affected. Differences between all treatments were small at N rates up to 2 times the recommended rate but at 4 times, yield was reduced for Agrotain treated and untreated seed placed N. For treatments where liquid dribble band was compared to side banding little difference in yield was observed when soil residual N was high and precipitation was low. A reduction in yield was found when soil N and precipitation were low. Where the N supply from soil was large and precipitation higher, yield of dribble banded crop continued to respond after side banded crops had peaked
Automated alignment in mask-free photolithography enabled by micro-LED arrays
We present an automated control system for positioning on the micro scale, based on the principles of single pixel imaging and fluorescence. By using the projected output of a chequerboard array of CMOS controllable μ-LEDs at a suitable wavelength, we are able to spatially locate, track and automatically align to fluorescent markers. Using this system, positioning is demonstrated with accuracy on the order of 20 μm. We present a maskless photo-lithography system using the automated control capability and a second μ-LED array to photo-cure customisable structures in photoresist with alignment referenced to the fluorescent markers
Production and purification of chimeric HBc virus-like particles carrying influenza virus LAH domain as vaccine candidates
Background: The lack of a universal influenza vaccine is a global health problem. Interest is now focused on structurally conserved protein domains capable of eliciting protection against a broad range of influenza virus strains. The long alpha helix (LAH) is an attractive vaccine component since it is one of the most conserved influenza hemagglutinin (HA) stalk regions. For an improved immune response, the LAH domain from H3N2 strain has been incorporated into virus-like particles (VLPs) derived from hepatitis B virus core protein (HBc) using recently developed tandem core technology. Results: Fermentation conditions for recombinant HBc-LAH were established in yeast Pichia pastoris and a rapid and efficient purification method for chimeric VLPs was developed to match the requirements for industrial scale-up. Purified VLPs induced strong antibody responses against both group 1 and group 2 HA proteins in mice. Conclusion: Our results indicate that the tandem core technology is a useful tool for incorporation of highly hydrophobic LAH domain into HBc VLPs. Chimeric VLPs can be successfully produced in bioreactor using yeast expression system. Immunologic data indicate that HBc VLPs carrying the LAH antigen represent a promising universal influenza vaccine component
Elaboração e validação de escala diagramática para quantificação da severidade da antracnose em frutos de maracujá amarelo
Types I and II interferons upregulate the costimulatory CD80 molecule in monocytes via interferon regulatory factor-1
Enhancing organisational competitiveness via social media - a strategy as practice perspective
The affordances, popularity and pervasive use of social media platforms such as Facebook, Twitter and Instagram have made these platforms attractive to organisations for enhancing their competitiveness and creating business value. Despite this apparent significance of social media for businesses, they are struggling with the development of a social media strategy as well as understanding the implications of social media on practice within their organisations. This paper explores how social media has become a tool for competitiveness and its influence on organisational strategy and practice. Using the 'strategy as practice' lens and guided by the interpretivist philosophy, this paper uses the empirical case of a telecom organisation in Tanzania. The findings show that social media is influencing competitiveness through imitation and product development. Also, the findings indicate how social media affects the practices within an organisation, consequently making the social media strategy an emergent phenomenon
Metabotyping of docosahexaenoic acid - Treated alzheimer's disease cell model
10.1371/journal.pone.0090123PLoS ONE92-POLN
It Costs to Be Clean and Fit: Energetics of Comfort Behavior in Breeding-Fasting Penguins
), seabirds known to fast for up to one month during incubation shifts ashore.A time budget was estimated from focal and scan sampling field observations and the energy cost of comfort activities was calculated from the associated increase in heart rate (HR) during comfort episodes, using previously determined equations relating HR to energy expenditure. We show that incubating birds spent 22% of their daily time budget in comfort behavior (with no differences between day and night) mainly devoted to preening (73%) and head/body shaking (16%). During comfort behavior, energy expenditure averaged 1.24 times resting metabolic rate (RMR) and the corresponding energy cost (i.e., energy expended in excess to RMR) was 58 kJ/hr. Energy expenditure varied greatly among various types of comfort behavior, ranging from 1.03 (yawning) to 1.78 (stretching) times RMR. Comfort behavior contributed 8.8–9.3% to total daily energy expenditure and 69.4–73.5% to energy expended daily for activity. About half of this energy was expended caring for plumage.This study is the first to estimate the contribution of comfort behavior to overall energy budget in a free-living animal. It shows that although breeding on a tight energy budget, king penguins devote a substantial amount of time and energy to comfort behavior. Such findings underline the importance of comfort behavior for the fitness of colonial seabirds
Recommended from our members
Impact of phenolic-rich olive leaf extract on blood pressure, plasma lipids and inflammatory markers: a randomised controlled trial
Purpose
Dietary polyphenols have been demonstrated to favourably modify a number of cardiovascular risk markers such as blood pressure (BP), endothelial function and plasma lipids. We conducted a randomised, double-blind, controlled, crossover trial to investigate the effects of a phenolic-rich olive leaf extract (OLE) on BP and a number of associated vascular and metabolic measures.
Methods
A total of 60 pre-hypertensive [systolic blood pressure (SBP): 121–140 mmHg; diastolic blood pressure (DBP): 81–90 mmHg] males [mean age 45 (±SD 12.7 years, BMI 26.7 (±3.21) kg/m2] consumed either OLE (136 mg oleuropein; 6 mg hydroxytyrosol) or a polyphenol-free control daily for 6 weeks before switching to the alternate arm after a 4-week washout.
Results
Daytime [−3.95 (±SD 11.48) mmHg, p = 0.027] and 24-h SBP [−3.33 (±SD 10.81) mmHg, p = 0.045] and daytime and 24-h DBP [−3.00 (±SD 8.54) mmHg, p = 0.025; −2.42 (±SD 7.61) mmHg, p = 0.039] were all significantly lower following OLE intake, relative to the control. Reductions in plasma total cholesterol [−0.32 (±SD 0.70) mmol/L, p = 0.002], LDL cholesterol [−0.19 (±SD 0.56) mmol/L, p = 0.017] and triglycerides [−0.18 (±SD 0.48), p = 0.008] were also induced by OLE compared to control, whilst a reduction in interleukin-8 [−0.63 (±SD 1.13) pg/ml; p = 0.026] was also detected. Other markers of inflammation, vascular function and glucose metabolism were not affected.
Conclusion
Our data support previous research, suggesting that OLE intake engenders hypotensive and lipid-lowering effects in vivo
- …