Assessing design options for a Nutrient Trading System using an integrated model

Water quality in many New Zealand waterways is currently declining leading to lakes and rivers being closed for contact recreation such as swimming and potentially threatening our clean, green image. Much of this decline is associated with an increase in the nutrient loss from agriculture in the surrounding catchment. Nutrient trading systems are being considered in a number of catchments across the county to restrict the nutrient loss entering the waterways and thus improve the water quality. Such a system is currently being implemented in Lake Taupo and Environment Bay of Plenty is exploring actively the use of such a system to manage nutrient loss in the Lake Rotorua catchment. Yet the design of such systems is challenging. In a collaborative effort between Motu, NIWA and GNS-Science, we are developing a spatial, stochastic, dynamic simulation model, N-TRADER to simulate the effect of different aspects of nutrient trading policy for the Lake Rotorua catchment. This model combines the economics of land use and management decision making, the functioning of temporal nutrient allowance markets and a model of nutrient flows and lags and is based on the best available empirical information on the geophysical and economic conditions for this catchment. This paper will discuss the design of N-TRADER and some of the nutrient trading system design questions that we plan to explore with the model including what is the impact of different nutrient caps and what is the impact of higher transaction costs.Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Research and Development/Tech Change/Emerging Technologies,

Mechanism of action of nucleoside antibacterial natural product antibiotics

This article reviews the structures and biological activities of several classes of uridine-containing nucleoside antibiotics (tunicamycins, mureidomycins/pacidamycins/sansanmycins, liposidomycins/caprazamycins, muraymycins, capuramycins) that target translocase MraY on the peptidoglycan biosynthetic pathway. In particular, recent advances in structure-function studies, and recent X-ray crystal structures of translocase MraY complexed with muraymycin D2 and tunicamycin are described. The inhibition of other phospho-nucleotide transferase enzymes related to MraY by nucleoside antibiotics and analogues is also reviewed

Water Quality Management in Lake Rotorua: A comparison of Regulatory Approaches using the NManager Model

The life satisfaction approach has recently emerged as a new technique in the suite of options available to non-market valuation practitioners. This paper examines the influence of ecosystem diversity on the life satisfaction of residents of South East Queensland, Australia. It is found that, on average, a respondent is willing-to-pay approximately AUD$20,000 in household income per annum to obtain a one-unit improvement in ecosystem diversity. This result indicates that the life satisfaction effects of improvements in ecosystem diversity are substantial, and greater than the welfare effects implied by studies using more conventional non-market valuation techniques.Environmental Economics and Policy,

Does Complex Hydrology Require Complex Water Quality Policy? NManager Simulations for Lake Rotorua

This paper examines six different approaches to nutrient management, and simulates the economic costs and environmental impacts associated with them using NManager, a partial equilibrium simulation model developed by Motu and NIWA, the National Institute for Water and Atmospheric Research. We focus on Lake Rotorua in the Bay of Plenty in New Zealand, where the regional council is concerned with the decline in the lake's water quality and has set a goal to restore the lake to its condition during the 1960s. Reaching this goal will require significant reductions in the amount of nutrients discharged into the lake, especially from non-point sources such as farm land. Managing water quality is made difficult by the presence of groundwater lags in the catchment: nutrients that leach from the soil arrive at the lake over multiple years. The mitigation schemes we consider are land retirement, requiring best practice, explicit nitrogen limits on landowners, a simple nutrient trading scheme, and two more complex trading schemes that account for groundwater lags. We demonstrate that best practice alone is not sufficient to meet the environmental target for Lake Rotorua. Under an export trading scheme, the distribution of mitigation across the catchment is more cost effective than its distribution under explicit limits on landowners or land retirement. However, the more complex trading schemes do not result in sufficient, or sufficiently certain, gains in cost effectiveness over the simple trading scheme to justify the increase in complexity involved in their implementation.groundwater, Lake Rotorua, model, nutrients, nutrient trading, water quality, non-point source pollution

Bio-Inspired Approach to Modelling Retinal Ganglion Cells using System Identification Techniques

The processing capabilities of biological vision systems are still vastly superior to artificial vision, even though this has been an active area of research for over half a century. Current artificial vision techniques integrate many insights from biology yet they remain far-off the capabilities of animals and humans in terms of speed, power, and performance. A key aspect to modeling the human visual system is the ability to accurately model the behavior and computation within the retina. In particular, we focus on modeling the retinal ganglion cells (RGCs) as they convey the accumulated data of real world images as action potentials onto the visual cortex via the optic nerve. Computational models that approximate the processing that occurs within RGCs can be derived by quantitatively fitting the sets of physiological data using an input–output analysis where the input is a known stimulus and the output is neuronal recordings. Currently, these input–output responses are modeled using computational combinations of linear and nonlinear models that are generally complex and lack any relevance to the underlying biophysics. In this paper, we illustrate how system identification techniques, which take inspiration from biological systems, can accurately model retinal ganglion cell behavior, and are a viable alternative to traditional linear–nonlinear approaches

Economic Values for Perennial Ryegrass Traits in New Zealand Dairy Farm Systems

Perennial ryegrass (Lolium perenne L.) is the main species used in dairy pastures throughout New Zealand. There are approximately 30 perennial ryegrass cultivars sold commercially in New Zealand, but currently there is no evaluation system which allows farmers to compare the potential impact of different cultivars on the profitability of their farm business. Such an economic evaluation system requires information on performance values (PV) for cultivars which quantifies their performance with respect to the major productivity traits (herbage accumulation (HA, kg DM/ha), nutritive value and persistence) relative to a genetic base, and economic values (EV, Doyle and Elliott 1983) which estimate the additional profit resulting from each unit change in the trait of interest (Equation 1). Economic value = Δ operating profit/Δ trait of interest (1) This paper describes a system modelling approach developed to estimate EV for seasonal HA of pasture in the major dairying regions of New Zealand. This information is used in the DairyNZ Forage Value Index system (www.dairynzfvi.co.nz) which is being developed to include information on all three productivity traits for commercially available ryegrass cultivars

Development of a Forage Evaluation System for Perennial Ryegrass Cultivar and Endophyte Combinations in New Zealand Dairy Systems

An economic index for perennial ryegrass (Lolium perenne L.) cultivars is a relatively new concept, although recently introduced in Ireland (McEvoy et al. 2011). By contrast, in dairy cattle breeding, the concept of an economic index rating animals and economic values underlying that index is well entrenched (Philipson et al. 1994; Veerkamp, 1998). Historically, forage evaluation data for individual cultivars were either displayed using absolute numbers for seasonal dry matter production within a season or across all seasons with a notation to indicate statistical differences, or percentage values where a reference cultivar is 100. The adoption of an economic index and routine evaluation approach for perennial ryegrass provides a method to identify traits of economic importance to focus plant breeding efforts better and to provide clarity for farmers around predicting cultivars that will maximise farm profit. It also allows for routine tracking of genetic gain of individual traits and the economic index. In this paper, the economic based forage evaluation techniques now used in New Zealand for perennial ryegrass cultivar/endophyte combinations are presented