Nutrient management on the Lincoln University dairy farm: "nutrient budgeting for efficient production"

Nutrient management plays an important role in any dairy farming system. Soil fertility status and fertiliser inputs are key drivers of pasture and animal production, whilst fertiliser represents a significant annual cost to the farm. At the same time, intensive agricultural systems also face the challenge of minimising or reducing nutrient loss in order to maintain environmental quality. Therefore 'best practice' may involve nutrient management in terms of balancing production, economic, environmental and efficiency goals. With ever increasing regulation and compliance requirements for the New Zealand farmer, best practice nutrient management will play an increasingly important role in achieving long term sustainability of the farming system. This paper gives an overview of the use of nutrient budgeting as a method of effective and efficient on-farm nutrient management. The paper will focus on nutrient management on the Lincoln University Dairy Farm (LUDF), including soil fertility monitoring and targets, the decision making process and the use of the nutrient budget output. Aspects of environmental research on the LUDF will also be discussed, including the quantification of nitrogen (N) losses, and results from research into nitrogen loss mitigation technology (eco-n nitrification inhibitor)

Effects of a Self-Selected Pace on VO2max during a Running Test to Volitional Exhaustion

Please view abstract in the attached PDF file

Confirmation of co-denitrification in grazed grassland

peer-reviewedPasture-based livestock systems are often associated with losses of reactive forms of nitrogen (N) to the environment. Research has focused on losses to air and water due to the health, economic and environmental impacts of reactive N. Di-nitrogen (N2) emissions are still poorly characterized, both in terms of the processes involved and their magnitude, due to financial and methodological constraints. Relatively few studies have focused on quantifying N2 losses in vivo and fewer still have examined the relative contribution of the different N2 emission processes, particularly in grazed pastures. We used a combination of a high 15N isotopic enrichment of applied N with a high precision of determination of 15N isotopic enrichment by isotope-ratio mass spectrometry to measure N2 emissions in the field. We report that 55.8 g N m−2 (95%, CI 38 to 77 g m−2) was emitted as N2 by the process of co-denitrification in pastoral soils over 123 days following urine deposition (100 g N m−2), compared to only 1.1 g N m−2 (0.4 to 2.8 g m−2) from denitrification. This study provides strong evidence for co-denitrification as a major N2 production pathway, which has significant implications for understanding the N budgets of pastoral ecosystems.The authors are grateful for the funding that was provided through the Research Stimulus Fund Program administered by the Department of Agriculture & Food under the National Development Plan 2007–2013 RSF 07536. The first author is grateful for the funding provided by Teagasc through the Walsh Fellowship Scheme

Scale-invariant magnetoresistance in a cuprate superconductor

The anomalous metallic state in high-temperature superconducting cuprates is masked by the onset of superconductivity near a quantum critical point. Use of high magnetic fields to suppress superconductivity has enabled a detailed study of the ground state in these systems. Yet, the direct effect of strong magnetic fields on the metallic behavior at low temperatures is poorly understood, especially near critical doping, $x=0.19$. Here we report a high-field magnetoresistance study of thin films of \LSCO cuprates in close vicinity to critical doping, $0.161\leq x\leq0.190$. We find that the metallic state exposed by suppressing superconductivity is characterized by a magnetoresistance that is linear in magnetic field up to the highest measured fields of $80$T. The slope of the linear-in-field resistivity is temperature-independent at very high fields. It mirrors the magnitude and doping evolution of the linear-in-temperature resistivity that has been ascribed to Planckian dissipation near a quantum critical point. This establishes true scale-invariant conductivity as the signature of the strange metal state in the high-temperature superconducting cuprates.Comment: 10 pages, 3 figure

Green Nanochemistry:Metal Oxide Nanoparticles and Porous Thin Films from Bare Metal Powders

Cataloged from PDF version of article.A universal, simple, robust, widely applicable and cost-effective aqueous process is described for a controlled oxidative dissolution process of micrometer-sized metal powders to form high-purity aqueous dispersions of colloidally stable 3-8 nm metal oxide nanoparticles. Their utilization for making single and multilayer optically transparent high-surface-area nanoporous films is demonstrated. This facile synthesis is anticipated to find numerous applications in materials science, engineering, and nanomedicine. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

A Single-Institution Review of Portosystemic Shunts in Children: An Ongoing Discussion

Purpose. Review the safety and long-term success with portosystemic shunts in children at a single institution. Methods. An IRB-approved, retrospective chart review of all children ages 19 and undergoing surgical portosystemic shunt from January 1990–September 2008. Results. Ten patients were identified, 8 females and 2 males, with a mean age of 15 years (range 5–19 years). Primary diagnoses were congenital hepatic fibrosis (5), hepatic vein thrombosis (2), portal vein thrombosis (2), and cystic fibrosis (1). Primary indications were repeated variceal bleeding (6), symptomatic hypersplenism (2), and significant liver dysfunction (2). Procedures performed were distal splenorenal bypass (4), side-to-side portocaval shunt (3), proximal splenorenal shunt (2), and an interposition H-graft portocaval shunt (1). There was no perioperative mortality and only minor morbidity. Seventy percent of patients had improvement of their symptoms. Eighty percent of shunts remained patent. Two were occluded at a median follow-up of 50 months (range 0.5–13.16 years). Two patients underwent subsequent liver transplantation. Two patients died at 0.5 and 12.8 years postoperatively, one from multisystem failure with cystic fibrosis and one from post-operative transplant complications. Conclusions. The need for portosystemic shunts in children is rare. However, in the era of liver transplantation, portosystemic shunts in selected patients with well-preserved liver function remains important. We conclude that portosystemic shunts are safe and efficacious in the control of variceal hemorrhage and symptoms related to hypersplenism

Confirmation of co-denitrification in grazed grassland

Pasture-based livestock systems are often associated with losses of reactive forms of nitrogen (N) to the environment. Research has focused on losses to air and water due to the health, economic and environmental impacts of reactive N. Di-nitrogen (N₂) emissions are still poorly characterized, both in terms of the processes involved and their magnitude, due to financial and methodological constraints. Relatively few studies have focused on quantifying N₂ losses in vivo and fewer still have examined the relative contribution of the different N₂ emission processes, particularly in grazed pastures. We used a combination of a high ¹⁵N isotopic enrichment of applied N with a high precision of determination of ¹⁵N isotopic enrichment by isotope-ratio mass spectrometry to measure N₂ emissions in the field. We report that 55.8 g N m⁻² (95%, CI 38 to 77 g m⁻²) was emitted as N₂ by the process of co-denitrification in pastoral soils over 123 days following urine deposition (100 g N m⁻²), compared to only 1.1 g N m⁻² (0.4 to 2.8 g m⁻²) from denitrification. This study provides strong evidence for co-denitrification as a major N₂ production pathway, which has significant implications for understanding the N budgets of pastoral ecosystems

From Service to Experience: Understanding and Defining the Hospitality Business

Failure adequately to define or understand hospitality as a commercial phenomenon has created a fragmented academic environment and a schizophrenia in the industry that has the potential to limit its development as a global industry. This article suggests that, by redefining hospitality as behaviour and experience, a new perspective emerges that has exciting implications for the management of hospitality businesses. A framework to describe hospitality in the commercial domain is proposed. This framework suggests a focus on the host–guest relationship, generosity, theatre and performance, ‘lots of little surprises’, and the security of strangers – a focus that provides guests with experiences that are personal, memorable and add value to their lives