Revaluing public sector food procurement in Europe: an action plan for sustainability

This report on Revaluing Public Sector Food Procurement is the result of a unique collaboration between policy-makers, practitioners and scientists working together during the Foodlinks project. The idea for the report emerged during the initial stages of experimenting with how we exchanged our knowledge on public sector food procurement that came from our work within municipal administrations, urban and national governments, European platforms, civil society and the wider academic community. We wanted to ‘make’ a report together that reflects not only the reality of devising and implementing innovative approaches to public sector food procurement throughout Europe, but also offers an Action Plan to help and encourage urban governments to take up the challenge of more sustainable purchasing practices. This is the result of that work. The report was written as a joint collaboration over a number of months using a wiki on a web-based platform that was also open to other members of our knowledge-based Community of Practic

Concurrent respiratory motion correction of abdominal PET and dynamic contrast-enhanced-MRI using a compressed sensing approach

We present an approach for concurrent reconstruction of respiratory motion-compensated abdominal dynamic contrast-enhanced (DCE)-MRI and PET data in an integrated PET/MR scanner. The MR and PET reconstructions share the same motion vector fields derived from radial MR data; the approach is robust to changes in respiratory pattern and does not increase the total acquisition time. Methods: PET and DCE-MRI data of 12 oncologic patients were simultaneously acquired for 6 min on an integrated PET/MR system after administration of 18F-FDG and gadoterate meglumine. Goldenangle radial MR data were continuously acquired simultaneously with PET data and sorted into multiple motion phases on the basis of a respiratory signal derived directly from the radial MR data. The resulting multidimensional dataset was reconstructed using a compressed sensing approach that exploits sparsity among respiratory phases. Motion vector fields obtained using the full 6-min (MC6-min) and only the last 1 min (MC1-min) of data were incorporated into the PET reconstruction to obtain motion-corrected PET images and in an MR iterative reconstruction algorithm to produce a series of motion-corrected DCE-MR images (moco-GRASP). The motioncorrection methods (MC6-min and MC1-min) were evaluated by qualitative analysis of the MR images and quantitative analysis of SUVmax and SUVmean, contrast, signal-to-noise ratio (SNR), and lesion volume in the PET images. Results: Motion-corrected MC6-min PET images demonstrated 30%, 23%, 34%, and 18% increases in average SUVmax, SUVmean, contrast, and SNR and an average 40% reduction in lesion volume with respect to the non-motion-corrected PET images. The changes in these figures of merit were smaller but still substantial for the MCMC1-min protocol: 19%, 10%, 15%, and 9% increases in average SUVmax, SUVmean, contrast, and SNR; and a 28% reduction in lesion volume. Moco-GRASP images were deemed of acceptable or better diagnostic image quality with respect to conventional breath-hold Cartesian volumetric interpolated breath-hold examination acquisitions. Conclusion: We presented a method that allows the simultaneous acquisition of respiratory motion-corrected diagnostic quality DCE-MRI and quantitatively accurate PET data in an integrated PET/MR scanner with negligible prolongation in acquisition time compared with routine PET/DCE-MRI protocols

Revaluing Public Sector Food Procurement In Europe : An Action Plan for Sustainability

This report on Revaluing Public Sector Food Procurement is the result of a unique collaboration between policy-makers, practitioners and scientists working together during the Foodlinks project. The idea for the report emerged during the initial stages of experimenting with how we exchanged our knowledge on public sector food procurement that came from our work within municipal administrations, urban and national governments, European platforms, civil society and the wider academic community. We wanted to ‘make’ a report together that reflects not only the reality of devising and implementing innovative approaches to public sector food procurement throughout Europe, but also offers an Action Plan to help and encourage urban governments to take up the challenge of more sustainable purchasing practices. This is the result of that work. The report was written as a joint collaboration over a number of months using a wiki on a web-based platform that was also open to other members of our knowledge-based Community of Practic

The Role of Risk and Transaction Costs in Contract Design: Evidence from Farmland Lease Contracts in U.S. Agriculture

The objective of this article is to provide new empirical evidence on landlord-tenant choices of share versus cash-rent contracts in U.S. agriculture. The focus is on the contribution of explanatory variables that represent transaction costs, risk-sharing incentives, or both. An empirical model of contract choice is tested against the 1999 Agricultural Economics and Land Ownership Survey (AELOS) and finds mixed evidence for low transaction cost and risk-sharing-incentive motives for landlord-tenant choices of a share versus cash-rent contract. However, the behavior of landlords and tenants is consistent with them being risk averse. Although it is standard to control for the riskiness of the principal's task that is contracted, we find that other attributes of the landlord are an important part of a relatively complex story for U.S. land tenancy contacting. The latter results have generally been ignored in other published landlord-tenant contracting studies. Copyright 2009, Oxford University Press.

Volumetric and Functional Activity Lateralization in Healthy Subjects and Patients with Focal Epilepsy:Initial Findings in a 7T MRI Study

BACKGROUND AND PURPOSE In 30% of the patients with focal epilepsy, an epileptogenic lesion cannot be visually detected with structural MRI. Ultra-high field MRI may be able to identify subtle pathology related to the epileptic focus. We set out to assess 7T MRI-derived volumetric and functional activity lateralization of the hippocampus, hippocampal subfields, temporal and frontal lobe in healthy subjects and MRI-negative patients with focal epilepsy. METHODS Twenty controls and 10 patients with MRI-negative temporal or frontal lobe epilepsy (TLE and FLE, respectively) underwent a 7T MRI exam. T-1-weigthed imaging and resting-state fMRI was performed. T-1-weighted images were segmented to yield volumes, while from fMRI data, the fractional amplitude of low frequency fluctuations was calculated. Subsequently, volumetric and functional lateralization was calculated from left-right asymmetry. RESULTS In controls, volumetric lateralization was symmetric, with a slight asymmetry of the hippocampus and subiculum, while functional lateralization consistently showed symmetry. Contrarily, in epilepsy patients, regions were less symmetric. In TLE patients with known focus, volumetric lateralization in the hippocampus and hippocampal subfields was indicative of smaller ipsilateral volumes. These patients also showed clear functional lateralization, though not consistently ipsilateral or contralateral to the epileptic focus. TLE patients with unknown focus showed an obvious volumetric lateralization, facilitating the localization of the epileptic focus. Lateralization results in the FLE patients were less consistent with the epileptic focus. CONCLUSION MRI-derived volume and fluctuation amplitude are highly symmetric in controls, whereas in TLE, volumetric and functional lateralization effects were observed. This highlights the potential of the technique

Time-efficient measurement of subtle blood-brain barrier leakage using a T-1 mapping MRI protocol at 7 T

Purpose Blood-brain barrier (BBB) disruption is commonly measured with DCE-MRI using continuous dynamic scanning. For precise measurement of subtle BBB leakage, a long acquisition time (&gt;20 minutes) is required. As extravasation of the contrast agent is slow, discrete sampling at strategic time points might be beneficial, and gains scan time for additional sequences. Here, we aimed to explore the feasibility of a sparsely sampled MRI protocol at 7 T.Methods The scan protocol consisted of a precontrast quantitative T-1 measurement, using an MP2RAGE sequence, and after contrast agent injection, a fast-sampling dynamic gradient-echo perfusion scan and two postcontrast quantitative T-1 measurements were applied. Simulations were conducted to determine the optimal postcontrast sampling time points for measuring subtle BBB leakage. The graphical Patlak approach was used to quantify the leakage rate (K-i) and blood plasma volume (v(p)) of normal-appearing white and gray matter.Results The simulations showed that two postcontrast T-1 maps are sufficient to detect subtle leakage, and most sensitive when the last T-1 map is acquired late, approximately 30 minutes, after contrast agent administration. The in vivo measurements found K-i and v(p) values in agreement with other studies, and significantly higher values in gray matter compared with white matter (both p = .04).Conclusion The sparsely sampled protocol was demonstrated to be sensitive to quantify subtle BBB leakage, despite using only three T-1 maps. Due to the time-efficiency of this method, it will become more feasible to incorporate BBB leakage measurements in clinical research MRI protocols.</p

Cerebral volume is unaffected after pre-eclampsia

OBJECTIVE: Pre-eclampsia, a hypertensive complication of pregnancy, has been associated with cardiovascular, cerebrovascular, and/or psychological complaints. Signs of an altered brain morphology and more white matter hyperintensities during and shortly after preeclampsia were observed in some, but not all, earlier studies. Here, cerebral volumes, the number of white matter hyperintensities and the age-related effects were compared in formerly pre-eclamptic women and women with normotensive gestational history. METHODS: Structural 7-Tesla magnetic resonance images of the cerebrum were acquired of 59 formerly pre-eclamptic women (aged 37±6 years, 0.5-16 years postpartum) and 20 women with normotensive pregnancies (aged 39±5 years, 1-18 years postpartum). Fazekas scores were obtained to assess white matter hyperintensity load. Volumes of the whole brain, gray and white matter, brain lobes, ventricular cerebrospinal fluid (CSF), and pericortical CSF were calculated after semi-automatic segmentation. Group differences were analyzed with ANCOVA and Bayes factors. Results were adjusted for age, educational attainment and total intracranial volume. Effects of age on cerebral volumes was analyzed using a linear regression analysis. RESULTS: No changes in global and local brain volumes were observed between formerly pre-eclamptic and control women. Also, no difference in white matter hyperintensity load was observed. Independent of pre-eclamptic history, gray matter volume significantly decreased with age, while ventricular and peri-cortical CSF volumes significantly increased with age. CONCLUSIONS: Volumetric changes of the cerebrum are age-related, but independent of a pre-eclamptic history in the first two decades after childbirth. No evidence for more white matter lesions after pre-eclampsia was found. This article is protected by copyright. All rights reserved