Sven Petersson

We examine the current status of greenhouse gas inventories of the sector Land Use, Land-Use Change and Forestry (LULUCF), in European countries, with specific focus on the utilization of National Forest Inventory (NFI) programs. LULUCF inventory is an integral part of the reporting obligations under the United Nations Framework Convention on Climate Change (UNFCCC) and its Kyoto Protocol. The analysis is based on two questionnaires prepared by the COST Action E43 “Harmonisation of National Forest Inventories in Europe”, which were answered by greenhouse gas reporting experts in European countries. The following major conclusions can be drawn from the analysis: 1) definitions used to obtain carbon pool change estimates vary widely among countries and are not directly comparable 2) NFIs play a key role for LULUCF greenhouse gas estimation and reporting under UNFCCC, and provide the fundamental data needed for the estimation of carbon stock changes covering not only living biomass...

ABSTRACT Most European countries have signed the United Nations Framework Convention on climate change and its Kyoto Protocol. Because the European Union is a party to the convention just like the individual countries, there is a need for harmonizing emissions reporting. This specifically applies to the Land Use, Land-Use Change, and Forestry sector, for which harmonized reporting is complex and generally challenging. For example, parties use a variety of different methods for estimating emissions and removals, ranging from application of default factors to advanced methods adapted to national circumstances, such as ongoing field inventories. In this study, we demonstrate that without harmonization, national definitions and methods lead to inconsistent estimates. Based on case studies in Finland, Germany, Norway, Portugal, Slovenia, and Sweden, we conclude that common reference definitions and country-specific bridges are means to harmonize the estimates and make greenhouse gas reporting from forests comparable across countries. FOR. SCI. 58(3):248-256.

Evaluate spiral three-dimensional (3D) phase contrast MRI for the assessment of turbulence and velocity in stenotic flow. A-stack-of-spirals 3D phase contrast MRI sequence was evaluated in vitro against a conventional Cartesian sequence. Measurements were made in a flow phantom with a 75% stenosis. Both spiral and Cartesian imaging were performed using different scan orientations and flow rates. Volume flow rate, maximum velocity and turbulent kinetic energy (TKE) were computed for both methods. Moreover, the estimated TKE was compared with computational fluid dynamics (CFD) data. There was good agreement between the turbulent kinetic energy from the spiral, Cartesian and CFD data. Flow rate and maximum velocity from the spiral data agreed well with Cartesian data. As expected, the short echo time of the spiral sequence resulted in less prominent displacement artifacts compared with the Cartesian sequence. However, both spiral and Cartesian flow rate estimates were sensitive to displacement when the flow was oblique to the encoding directions. Spiral 3D phase contrast MRI appears favorable for the assessment of stenotic flow. The spiral sequence was more than three times faster and less sensitive to displacement artifacts when compared with a conventional Cartesian sequence. Magn Reson Med, 2015. © 2015 Wiley Periodicals, Inc.

To develop and evaluate retrospectively gated spiral readout four-dimensional (4D) flow MRI for intracardiac flow analysis. Retrospectively gated spiral 4D flow MRI was implemented on a 1.5-tesla scanner. The spiral sequence was compared against conventional Cartesian 4D flow (SENSE [sensitivity encoding] 2) in seven healthy volunteers and three patients (only spiral). In addition to comparing flow values, linear regression was used to assess internal consistency of aortic versus pulmonary net volume flows and left ventricular inflow versus outflow using quantitative pathlines analysis. Total scan time with spiral 4D flow was 44% ± 6% of the Cartesian counterpart (13 ± 3 vs. 31 ± 7 min). Aortic versus pulmonary flow correlated strongly for the spiral sequence (P < 0.05, slope = 1.03, R(2) = 0.88, N = 10), whereas the linear relationship for the Cartesian sequence was not significant (P = 0.06, N = 7). Pathlines analysis indicated good data quality for the spiral (P < 0.05, slo...