Vegetation of Maple-leaved Oak Sites on Sugarloaf and Magazine Mountains, Arkansas

We conducted an analysis of the vegetation of the maple-leaved oak sites on Sugarloaf and Magazine Mountains, Arkansas, during September and October of 1993. The woody vegetation was sampled using the point-quarter method; on Sugarloaf Mountain five transects were sampled (950 m) and on Magazine Mountain four transects were sampled (710 m). Soil samples from each site were collected and analyzed for 15 factors. In total 27 species were recorded and measured for both sites, 18 for Sugarloaf and 19 for Magazine. The Sugarloaf site can be described as a Quercus-Juniperus community and the Magazine site can be described as a Juniperus-Carya-Fraxinus community. Qualitative observations for the maple leaved oak sites on Porter and Pryor Mountains, Arkansas, are also included

Nonergodicity transitions in colloidal suspensions with attractive interactions

The colloidal gel and glass transitions are investigated using the idealized mode coupling theory (MCT) for model systems characterized by short-range attractive interactions. Results are presented for the adhesive hard sphere and hard core attractive Yukawa systems. According to MCT, the former system shows a critical glass transition concentration that increases significantly with introduction of a weak attraction. For the latter attractive Yukawa system, MCT predicts low temperature nonergodic states that extend to the critical and subcritical region. Several features of the MCT nonergodicity transition in this system agree qualitatively with experimental observations on the colloidal gel transition, suggesting that the gel transition is caused by a low temperature extension of the glass transition. The range of the attraction is shown to govern the way the glass transition line traverses the phase diagram relative to the critical point, analogous to findings for the fluid-solid freezing transition.Comment: 11 pages, 7 figures; to be published in Phys. Rev. E (1 May 1999

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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[Energy and emissions of CO2, NOx and SO2 in the scenarios of the third Environmental Outlook. Background report to the 3rd Environmental Outlook 1990-2015.]

Abstract niet beschikbaarIn 1993 the Dutch environmental policy is evaluated. Part of this evaluation is an outlook on the energy consumption, the energy supply and the energy related emissions of CO2, NOx and SO2. This outlook is made in a close collaboration between the Central Planning Bureau (CPB), the Netherlands Energy Research Centre (ECN) and the National Institute of Public Health and Environmental Protection (RIVM). This report is the background document which presents the results of this collaboration in the field of energy. The main conclusions are: * The use of energy will grow between 1990 and 2000 depending on economic growth and energy price level. When the economic growth is high the energy consumption increases 9-16%, with a low rate of economic growth it will be 3-9%. After 2000 the energy consumption rises 0,5-1,5% a year. *Closely connected with the energy consumption the emission of CO2 will rise in most scenario's up to the year 2000. Only in a situation of low economic growth and high energy prices a small decrease of the emission takes place. In the next century the emission of CO2 will continue to rise. Only in this situation the emission goal for 2000 is within reach. * The emission of the acid components SO2 and NOx will decline. The goal for SO2 emission will likely be reached. This is not the case for the emission of NOx. Traffic is the main sector responsible for not reaching this goal.DGM/SP ECN EZ CP

Impact of land use change and rainfall on sediment and carbon accumulation in a water reservoir of North Thailand

The lifespan of many tropical water reservoirs is limited by siltation due to soil erosion in the watershed. The objectives of this study were to determine, the amount of catchment-derived organic carbon accumulated in sediments of a reservoir of North Thailand and to relate it with the history of cultivation and rainfall regime in the watershed. Over a twelve-years period (1995-2006) since impoundment sediment delivery was high (ca. 19.6 Mg ha(-1) yr(-1)). The yearly supply of catchment-derived material was composed of coarse sediment deposits near the main inlets and of fine laminated sediment accumulations in deep-water environments. Their stable carbon isotope composition indicated that soil organic matter was the main source of organic carbon preserved in sediments (ca. 83 wt.%). Fine sediments derived from suspended loads exported from the watershed by runoff and stream waters were related to erosive rainfall, to the extent of area under annual cropping and to crop change with a marked increase after the replacement of beans by maize. However, sediment accumulation did not respond linearly to extreme rainfall events, as shown by the supply of nearly 48% of the total amount of sediments by a single exceptional flood. Total organic carbon storage in sediments reached ca. 23.8 MgC ha(-1) yr(-1) in 2006, twelve years after impoundment, falling in the upper range of small to medium size reservoirs with agricultural catchments

FDG-PET as a predicitve marker for primary resistance to imatinib (IM) in patients with gastrointestinal stromal tumors (GIST)

10051 Background: A small number of patients (pts) with advanced GIST show primary resistance to IM, defined as progressive disease (PD) at first CT evaluation. Early recognition of resistance could prohibit side effects and save costs of ineffective treatment. IM can induce a rapid decrease in (18)F-fluorodeoxyglucose (FDG) uptake in GIST. Aim of this study is to investigate if early change in tumor FDG uptake predicts primary IM resistance. METHODS: Consecutive pts with metastatic or locally advanced GIST had FDG-PET scans before and 1 week after start of IM. Maximum Standardized Uptake Value (SUVmax) was determined and mean SUVmax for a maximum of 5 lesions per pt was calculated. Relationship between PET response (according to EORTC guidelines) and CT response (according to RECIST and Choi) after 2 months of treatment, was investigated. RESULTS: 22 male and 14 female pts were included, mean age 62 years (range 23-81). 29 pts were treated in a palliative and 7 in a neo-adjuvant setting. 6 pts were not evaluable for PET response: 4 pts had no FDG-avid lesions, 2 pts had discordant PET scan protocols. 81 tumor lesions in 30 pts were quantified. Mean SUVmax on the first scan was 7.4 (SD 3.8, range 2.2-18.4) and on the second scan 3.0 (SD 2.1, range 0.1-11.8) (P<0.001). 26 pts had a metabolic response, 4 pts had metabolically stable disease. After 8 weeks of treatment 29 and 23 pts were evaluable according to RECIST and Choi criteria respectively (see table). PET response had a high positive predictive value (PPV) for clinical benefit (complete response (CR) or partial response (PR) or stable disease (SD)) according to RECIST: 92% (95% CI 74-99%) and Choi criteria: 95% (95% CI 76-100%). However, the false negative rate was 11% (95% CI 2-30%) resp. 9% (95% CI 1-30%) and pts with PD had a PET response. CONCLUSIONS: Although early FDG-PET response has a high PPV for clinical benefit from IM in pts with GIST, FDG-PET scans can not be used to predict primary resistance. [Table: see text]