62 research outputs found
Policy to Encourage Carbon Sequestration in Plantation Forests
Carbon sequestration in plantation forests provides the main means by which New Zealand will meet its international climate change obligations in the first commitment period of the Kyoto Protocol (2008-2012). However, without active policy, forests are unlikely to contribute as much in subsequent commitment periods. This research paper provides the background for examining policy measures for encouraging carbon sequestration in plantation forests in New Zealand. Part I focuses on providing factual information and positive analysis of: key domestic and international regulations; information on New Zealand forests, the forestry industry and forest profitability; discussion of land-use decision making, including the central question of what influences conversion of farmland to forestry; and forest carbon ecology. Part II moves on to normative analysis of policy design. It discusses how including considerations of the value of carbon sequestration and storage changes optimal land-use behaviour, and outlines key issues that need to be addressed when developing a policy to encourage sequestration and storage in a pragmatic way. Finally, the paper identifies a number of key areas where we need more information before we can make well-informed choices about policy design. Future work will endeavour to identify and evaluate policies that would effectively encourage sequestration.climate, forest, carbon sequestration, policy, New Zealand, Kyoto
Policy to Encourage Carbon Sequestration in Plantation Forests
Carbon sequestration in plantation forests provides the main means by which New Zealand will meet its international climate change obligations in the first commitment period of the Kyoto Protocol (2008–2012). However, without active policy, forests are unlikely to contribute as much in subsequent commitment periods. This research paper provides the background for examining policy measures for encouraging carbon sequestration in plantation forests in New Zealand. Part I focuses on providing factual information and positive analysis of: key domestic and international regulations; information on New Zealand forests, the forestry industry and forest profitability; discussion of land-use decision making, including the central question of what influences conversion of farmland to forestry; and forest carbon ecology. Part II moves on to normative analysis of policy design. It discusses how including considerations of the value of carbon sequestration and storage changes optimal land-use behaviour, and outlines key issues that need to be addressed when developing a policy to encourage sequestration and storage in a pragmatic way. Finally, the paper identifies a number of key areas where we need more information before we can make well- informed choices about policy design. Future work will endeavour to identify and evaluate policies that would effectively encourage sequestration.climate, forest, carbon sequestration, policy, New Zealand, Kyoto
The likely regional impacts of an agricultural emissions policy in New Zealand: Preliminary analysis
Hendy and Kerr (2005b) find that an emissions charge on agricultural methane and nitrous oxide of $25 per tonne of carbon dioxide (CO2) equivalent would be likely to reduce New Zealand's net land-use related emissions for commitment period one in the order of 3%, with full accounting. The costs per farmer and as a percentage of profit would be very high. This paper considers the regional impacts of such a policy in New Zealand by allocating the emission charge across space according to the location of animals. We then combine our emissions charge information with data on the socio-economic characteristics of the affected areas. Obviously rural areas are heavily affected. In many respects, for example median income, ethnic mix, and percentage of working people with a university degree, the rural areas most affected have very similar socio-economic characteristics to other parts of rural New Zealand. Only in two ways do they appear to differ. Our findings indicate that areas with high emission costs tend to have high employment rates, but that they also have a disproportionately high number of unqualified people.climate change, land use, social impacts, methane, nitrous oxide, dairy, sheep, beef, distribution of costs, regional
The likely regional impacts of an agricultural emissions policy in New Zealand: Preliminary analysis
Hendy and Kerr (2005b) find that an emissions charge on agricultural methane and nitrous oxide of $25 per tonne of carbon dioxide (CO2) equivalent would be likely to reduce New Zealand’s net land-use related emissions for commitment period one in the order of 3%, with full accounting. The costs per farmer and as a percentage of profit would be very high. This paper considers the regional impacts of such a policy in New Zealand by allocating the emission charge across space according to the location of animals. We then combine our emissions charge information with data on the socio-economic characteristics of the affected areas. Obviously rural areas are heavily affected. In many respects, for example median income, ethnic mix, and percentage of working people with a university degree, the rural areas most affected have very similar socio-economic characteristics to other parts of rural New Zealand. Only in two ways do they appear to differ. Our findings indicate that areas with high emission costs tend to have high employment rates, but that they also have a disproportionately high number of unqualified people.climate change, land use, social impacts, methane, nitrous oxide, dairy, sheep, beef, distribution of costs, regional
Influence of nerve cuff channel count and implantation site on the separability of afferent ENG
How fast is too fast? Boundaries to the perception of electrical stimulation of peripheral nerves
Transcutaneous electrical stimulation is a promising technique for providing prosthetic hand users with information about sensory events. However, questions remain over how to design the stimulation paradigms to provide users the best opportunity to discriminate these events. Here, we investigate if the refractory period influences how the amplitude of the applied stimulus is perceived. Twenty participants completed a two-alternative forced choice experiment. We delivered two stimuli spaced between 250 ms to 450 ms apart (inter-stimulus-interval, isi). The participants reported which stimulus they perceived as strongest. Each stimulus consisted of either a single or paired pulse delivered transcutaneously. The inter-pulse interval (ipi) for the paired pulse stimuli varied between 6 and 10 ms. We found paired pulses with an ipi of 6 ms were perceived stronger than a single pulse less often than paired pulses with an ipi of 8 ms (p = 0.001) or 10 ms (p < 0.0001). Additionally, we found when the isi was 250 ms, participants were less likely to identify the paired pulse as strongest, than when the isi was 350 or 450 ms. This study emphasizes the importance of basing stimulation paradigms on the underlying neural physiology. The results indicate there is an upper limit to the commonly accepted notion that higher stimulation frequencies lead to stronger perception. If frequency is to be used to encode sensory events, then the results suggest stimulus paradigms should be designed using frequencies below 125 Hz
Temporal modulation of the response of sensory fibers to paired-pulse stimulation
Multi-channel nerve cuff electrode arrays can provide sensory feedback to prosthesis users. To develop efficacious stimulation protocols, an understanding of the impact that spatio-temporal patterned stimulation can have on the response of sensory fibers is crucial. We used experimental and modelling methods to investigate the response of nerve fibers to paired-pulse stimulation. Nerve cuff electrode arrays were implanted for stimulation of the sciatic nerves of rats and the sensory compound action potentials were recorded from the L4 dorsal root. A model of the nerve cuff electrode array and sciatic nerve was also developed. The experimental and modelling results were compared. Experiments showed that it took 8 ms for the sensory fibers to completely recover from a conditioning stimulus, regardless of the relative position of the electrodes used for stimulation. The results demonstrate that the electrodes on the cuff cannot be considered independent. Additionally, at 120% of the threshold, there is a large overlap in the fibers that were activated by the different electrodes. If a stimulus paradigm considered the electrodes as independent, stimuli from the different electrodes would need to be interleaved, and the intervals between the stimuli should be greater than 8 ms
W:Ti flexible transversal electrode array for peripheral nerve stimulation: a feasibility study
The development of hardware for neural interfacing remains a technical challenge. We introduce a flexible, transversal intraneural tungsten:titanium electrode array for acute studies. We characterize the electrochemical properties of this new combination of tungsten and titanium using cyclic voltammetry and electrochemical impedance spectroscopy. With an in-vivo rodent study, we show that the stimulation of peripheral nerves with this electrode array is possible and that more than half of the electrode contacts can yield a stimulation selectivity index of 0.75 or higher at low stimulation currents. This feasibility study paves the way for the development of future cost-effective and easy-to-fabricate neural interfacing electrodes for acute settings, which ultimately can inform the development of technologies that enable bi-directional communication with the human nervous system
SenseBack - An implantable system for bidirectional neural interfacing
Chronic in-vivo neurophysiology experiments require highly miniaturized, remotely powered multi-channel neural interfaces which are currently lacking in power or flexibility post implantation. In this article, to resolve this problem we present the SenseBack system, a post-implantation reprogrammable wireless 32-channel bidirectional neural interfacing that can enable chronic peripheral electrophysiology experiments in freely behaving small animals. The large number of channels for a peripheral neural interface, coupled with fully implantable hardware and complete software flexibility enable complex in-vivo studies where the system can adapt to evolving study needs as they arise. In complementary ex-vivo and in-vivo preparations, we demonstrate that this system can record neural signals and perform high-voltage, bipolar stimulation on any channel. In addition, we demonstrate transcutaneous power delivery and Bluetooth 5 data communication with a PC. The SenseBack system is capable of stimulation on any channel with ±20 V of compliance and up to 315 μA of current, and highly configurable recording with per-channel adjustable gain and filtering with 8 sets of 10-bit ADCs to sample data at 20 kHz for each channel. To the best of our knowledge this is the first such implantable research platform offering this level of performance and flexibility post-implantation (including complete reprogramming even after encapsulation) for small animal electrophysiology. Here we present initial acute trials, demonstrations and progress towards a system that we expect to enable a wide range of electrophysiology experiments in freely behaving animals
Antenatal dexamethasone treatment transiently alters diastolic function in the mouse fetal heart
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