1. |
|
|
2. |
- McDonnell, J.J., et al.
(författare)
-
How old is streamwater? : Open questions in catchment transit time conceptualization, modelling and analysis
- 2010
-
Ingår i: Hydrological Processes. - : John Wiley & Sons. - 0885-6087 .- 1099-1085. ; 24:12, s. 1745-1754
-
Tidskriftsartikel (refereegranskat)abstract
- The time water spends travelling subsurface through a catchment to the stream network (i.e. the catchment water transit time) fundamentally describes the storage, flow pathway heterogeneity and sources of water in a catchment. The distribution of transit times reflects how catchments retain and release water and solutes that in turn set biogeochemical conditions and affect contamination release or persistence. Thus, quan- tifying the transit time distribution provides an important constraint on biogeochemical processes and catchment sensitivity to anthropogenic inputs, contamination and land-use change. Although the assumptions and limitations of past and present transit time modelling approaches have been recently reviewed (McGuire and McDonnell, 2006), there remain many fundamental research challenges for understanding how transit time can be used to quantify catchment flow processes and aid in the development and testing of rainfall–runoff models. In this Commen- tary study, we summarize what we think are the open research questions in transit time research. These thoughts come from a 3-day workshop in January 2009 at the International Atomic Energy Agency in Vienna. We attempt to lay out a roadmap for this work for the hydrological commu- nity over the next 10 years. We do this by first defining what we mean (qualitatively and quantitatively) by transit time and then organize our vision around needs in transit time theory, needs in field studies of tran- sit time and needs in rainfall – runoff modelling. Our goal in presenting this material is to encourage widespread use of transit time information in process studies to provide new insights to catchment function and to inform the structural development and testing of hydrologic models.
|
|
3. |
- Ekholm, S. E., et al.
(författare)
-
MRI staging using gadodiamide for soft-tissue tumors of the head and neck region. Results from a phase II trial and a 5-year clinical follow-up
- 2001
-
Ingår i: Eur J Radiol. - 0720-048X. ; 39:3, s. 168-75
-
Tidskriftsartikel (refereegranskat)abstract
- In order to document the safety, tolerability and efficacy of gadodiamide outside CNS, an open, non-drug comparative study was performed in patients with tumors of the head and neck region. Fifty adult patients were included and 48 patients received the contrast medium. The examinations were performed on a 1.5 T imager using transverse, non-enhanced T1- and PD-/T2-weighted conventional spin-echo sequences, followed by a contrast-enhanced transverse T1-weighted sequence. Post-contrast images provided more diagnostic information compared to unenhanced images in 33 of 48 patients (69%). This information was of significant help in four and of moderate help in 14 cases. Post-contrast images compared to non-enhanced T1-weighted showed improvement in lesion delineation for 29 of the 43 patients where a lesion was observed. Only in two patients was the diagnostic information lower post-contrast. A comparison between all pre-contrast images versus contrast medium enhanced showed post-contrast images to give more diagnostic information in 14 and less in nine patients. No patient experienced discomfort in relation to gadodiamide injection. Only one adverse event occurred which was described as thirst, being of moderate intensity. The 5-year clinical outcome was analyzed and compared with the pre-operative staging. The case-books of all patients were reviewed and in 44 patients all information could be found. Of those, 18 were still alive, one with active disease (AAD) and 17 with no evidence of disease (NED). Two of those four patients, where information was incomplete, showed NED and two had died. This trial showed that contrast-enhancement using gadodiamide for evaluation of soft tissue tumors in the head and neck region was safe and provided statistically significant more diagnostic information compared with unenhanced images. MRI, when compared with palpation/inspection, changed tumor staging in approximately 30% of all cases.
|
|
4. |
|
|
5. |
- Western, Benedikte, et al.
(författare)
-
Dropout from exercise trials among cancer survivors—An individual patient data meta-analysis from the POLARIS study
- 2024
-
Ingår i: Scandinavian Journal of Medicine and Science in Sports. - Chichester, West Sussex : Wiley-Blackwell Publishing Inc.. - 0905-7188 .- 1600-0838. ; 34:2, s. 1-10
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: The number of randomized controlled trials (RCTs) investigating the effects of exercise among cancer survivors has increased in recent years; however, participants dropping out of the trials are rarely described. The objective of the present study was to assess which combinations of participant and exercise program characteristics were associated with dropout from the exercise arms of RCTs among cancer survivors. Methods: This study used data collected in the Predicting OptimaL cAncer RehabIlitation and Supportive care (POLARIS) study, an international database of RCTs investigating the effects of exercise among cancer survivors. Thirty-four exercise trials, with a total of 2467 patients without metastatic disease randomized to an exercise arm were included. Harmonized studies included a pre and a posttest, and participants were classified as dropouts when missing all assessments at the post-intervention test. Subgroups were identified with a conditional inference tree. Results: Overall, 9.6% of the participants dropped out. Five subgroups were identified in the conditional inference tree based on four significant associations with dropout. Most dropout was observed for participants with BMI >28.4 kg/m2, performing supervised resistance or unsupervised mixed exercise (19.8% dropout) or had low-medium education and performed aerobic or supervised mixed exercise (13.5%). The lowest dropout was found for participants with BMI >28.4 kg/m2 and high education performing aerobic or supervised mixed exercise (5.1%), and participants with BMI ≤28.4 kg/m2 exercising during (5.2%) or post (9.5%) treatment. Conclusions: There are several systematic differences between cancer survivors completing and dropping out from exercise trials, possibly affecting the external validity of exercise effects. © 2024 The Authors. Scandinavian Journal of Medicine & Science In Sports published by John Wiley & Sons Ltd.
|
|
6. |
|
|