1,823 research outputs found
Towards the sustainable intensification of agriculture—a systems approach to policy formulation
The sustainable intensification of agriculture involves providing sufficient food and other ecosystem services without going beyond the limits of the earth’s system. Here a project management approach is suggested to help guide agricultural policy to deliver these objectives. The first step is to agree measurable outcomes, integrating formal policy goals with the often much less formal and much more diverse goals of individual farmers. The second step is to assess current performance. Ideally, this will involve the use of farm-scale metrics that can feed into process models that address social and environmental domains as well as production issues that can be benchmarked and upscaled to landscape and country. Some policy goals can be delivered by supporting ad hoc interventions, while others require the redesign of the farming system. A pipeline of research, knowledge and capacity building is needed to ensure the continuous increase in farm performance. System models can help prioritise policy interventions. Formal optimization of land use is only appropriate if the policy goals are clear, and the constraints understood. In practice, the best approach may depend on the scale of action that is required, and on the amount of resource and infrastructure available to generate, implement and manage policy
Anti-confocal assessment of middle ear inflammation
To improve the diagnostic prediction of recurrence of otitis media with effusion after surgery, an anti-confocal system combined with spectroscopic measurements is proposed to reject unwanted signals from the eardrum and assess the blood content. The anti-confocal system was experimentally evaluated on both optical middle ear phantom and human skin. Results showed effective rejection of signals from the eardrum using a central stop replacing the confocal pinhole, while still detecting signals from the middle ear mucosa. The system is sensitive to changes in blood content, but scattering and absorption characteristics of the eardrum can distort the measurement. Confocal detection of eardrum properties was shown to be a promising approach to correct measurements
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Long reaction times are associated with delayed brain activity in Lewy body dementia
A significant symptom of Lewy body dementia (LBD) is slow cognitive processing or bradyphrenia. In a previous fMRI task-based study, we found slower responses in LBD, accompanied by greater deactivation in the default mode network. In this study, we investigated the timing and magnitude of the activations and deactivations with respect to reaction time to determine whether the slower responses in LBD were associated with delayed neuronal activity. Using fMRI, we examined the magnitude and latency of activations and deactivations during an event-related attention task in 32 patients with LBD and 23 healthy controls using predefined regions of interest. Default mode network deactivations did not significantly differ in their timing between groups or task conditions, while the task-related activations in the parietal, occipital, frontal, and motor cortex were all significantly later in the LBD group. Repeating the analysis with reaction time as a parametric modulator of activation magnitude produced similar findings, with the reaction time modulator being significant in a number of regions including the default mode network, suggesting that the increased deactivation in LBD is partly explained by slower task completion. Our data suggest that the default mode network deactivation is initiated at the start of the task, and remains deactivated until its end, with the increased magnitude of deactivation in LBD reflecting the more prolonged cognitive processing in these patients. These data add substantially to our understanding of the neural origins of bradyphrenia, which will be essential for determining optimum therapeutic strategies for cognitive impairment in LBD.Funded by: National Institute for Health Research, Newcastle Biomedical Research Unit based at Newcastle Hospitals NHS Foundation Trust, Newcastle University, Wellcome Trust. Grant Number: WT088441M
How scalable is sustainable intensification?
Sustainable intensification is a concept of growing importance, yet it is in danger of becoming scientifically obsolete because of the diversity of meanings it has acquired. To avoid this, it is important to consider the various scales on which it can aid progress towards feeding human populations while also protecting our environment
Epigeal fauna of urban food production sites show no obvious relationships with soil characteristics or site area
Urban food production is a growing area of interest as a way of increasing food security, social capital and biodiversity. As food production relies upon ecosystem services provided by invertebrates (e.g. decomposition), it is important to understand the underlying factors affecting their distribution. Here we investigated the influence of soil characteristics and patch area on the abundance and diversity of epigeal invertebrates. Seventeen sites of different size from in and around Leeds, UK, were selected from an open source database on urban food production. Pitfall traps were placed along transects to collect beetles, springtails, and spiders. These invertebrates were identified and counted, adjusting total counts for the number of traps used at each location. Soil samples from the trap locations were homogenized, dried, and analysed to measure organic carbon content, moisture content, and pH, while productivity was assessed by growing radish Raphanus sativus on the soils under uniform conditions. This study found no evidence of correlation of epigeal abundance and diversity with site area or soil characteristics. These findings suggest that there is no evidence as yet of urban food production sites that are too small to be able to draw upon ecosystem services delivered by epigeal invertebrates
Visual cortical excitability in dementia with Lewy bodies.
Alterations in the visual system may underlie visual hallucinations in dementia with Lewy bodies (DLB). However, cortical excitability as measured by transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI) activation of lower visual areas (V1-3) to visual stimuli appear normal in DLB. We explored the relationship between TMS-determined phosphene threshold and fMRI-related visual activation and found a positive relationship between the two in controls but a negative one in DLB. This double dissociation suggests a loss of inhibition in the visual system in DLB, which may predispose individuals to visual dysfunction and visual hallucinations.The research was funded by an Intermediate Clinical Fellowship to J.-P.T. (WT088441MA) and also supported by the National Institute for Health Research (NIHR) Newcastle Biomedical Research Unit based at Newcastle upon Tyne Hospitals NHS Foundation Trust and Newcastle University. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.This is the final version of the article. It first appeared from the Royal College of Psychiatrists via http://dx.doi.org/10.1192/bjp.bp.114.15273
Is there a preference for PET or SPECT brain imaging in diagnosing dementia? The views of people with dementia, carers, and healthy controls
The design, calibration and usage of a solid scattering and absorbing phantom for near infra red spectroscopy.
Following a review of methods for measuring the optical properties of tissue, the
majority of this thesis is concerned with the design, construction, calibration and use of
a solid, tissue equivalent phantom.
The phantom material is a clear polyester plastic. This is obtained in
unpolymerised form, scattering particles and absorbing dyes are added to it, and it is
then polymerised to form a stable solid.
Purely scattering and absorbing phantoms were made separately, and their optical
properties were measured using a specially built system. This has a co-linear collimated
light source and detector, and measures the unscattered light transmitted through a
sample as a function of its thickness.
Other methods of measuring the optical coefficients of tissue were tested with
this phantom. One of these uses integrating spheres to measure the transmitted and
reflected light from a sample. A model of light transport (in this case a Monte Carlo
model) is used to convert these measurements into scattering and absorption coefficients.
It was found that the measurement of scattering coefficient was reasonably accurate, but
that the absorption coefficient was overestimated at the low values typical of tissue. A
measurement of the optical properties of bone was made with this system. The other
system investigated uses the diffusion theory to calculate optical properties from
measurements made through a thick slab.
The material was also employed to create a test phantom for near infrared
spectroscopy machines. This provides a diffusing medium with an attenuation that is
variable in discrete steps over three orders of magnitude. The relative attenuation
between steps is totally wavelength independent. This phantom was adopted by the EC
concerted action on near infrared spectroscopy and imaging.
Finally, the phantom was used to create test objects with which to investigate the
potential of imaging with infrared light
Making sense, discovering what works... Cross-agency collaboration in Child Welfare and Protection in Norway and Quebec
<p>This paper addresses the enabling and constraining factors that underpin inter-organizational collaboration in Child Welfare and Protection services in Norway and Quebec. Characterized by different regulatory systems, but with a common drive to hierarchically promote cross-agency collaboration, these jurisdictions provide the basis for two instructive and contrasting case studies on the subject. The paper builds on meta-ethnography as a means to synthesize and translate results from separate qualitative research undertakings carried out in each place. It argues that although a core set of properties may be identified as necessary for collaboratives to operate in a successful, sustainable manner; greater attention should be paid to how these properties interact with one another on the ground, given schemes’ particular scope and scale of objectives. Moreover, regulatory provisions aimed at stimulating or mandating cross-agency networks may align with collaborative capacity in various ways, occasionally in a mutually reinforcing, but sometimes antagonistic manner. The conclusions drawn have implications for both research and policy.</p
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