405 research outputs found
Lived experiences of âpeak waterâ in the high mountains of Nepal and Peru
Peak water describes the hydrological response of glacier-fed rivers to climate change, indicating that warming first drives increasing discharge until a glacier mass loss threshold is surpassed and discharge falls below values observed prior to contemporary climate warming. Although the physical principles of peak water are well understood and accepted, there remains little empirical work evaluating how hydrological dynamics associated with peak water are experienced by residents of high mountain communities at the frontlines of glacial change. In response, this studyâdrawing on 160 household interviews, 34 key informant interviews, and 4 focus groupsâuses a contextual vulnerability approach to characterize lived experiences of peak water in communities of the upper Manaslu region of the Nepal Himalaya and the Cordillera Huayhuash region of the Peruvian Andes. It problematizes characteristics of vulnerability postulated in the glacio-hydrological modelling literature by revealing unanticipated experiences of peak water dynamics on both the rising and falling limb of the peak water profile. The study complements existing glacio-hydrology literature, demonstrates the importance of social theoretical perspectives in the evaluation of human vulnerability to peak water, and provides insights that can help appropriately target scarce adaptation resources
Iceâocean interaction and calving front morphology at two west Greenland tidewater outlet glaciers
Warm, subtropical-originating Atlantic water (AW) has been identified as a
primary driver of mass loss across the marine sectors of the Greenland Ice
Sheet (GrIS), yet the specific processes by which this water mass interacts
with and erodes the calving front of tidewater glaciers is frequently modelled
and much speculated upon but remains largely unobserved. We present a suite of
fjord salinity, temperature, turbidity versus depth casts along with
glacial runoff estimation from Rink and Store glaciers, two major marine
outlets draining the western sector of the GrIS during 2009 and 2010. We
characterise the main water bodies present and interpret their interaction
with their respective calving fronts. We identify two distinct processes of
iceâocean interaction which have distinct spatial and temporal footprints:
(1) homogenous free convective melting which occurs across the calving front
where AW is in direct contact with the ice mass, and (2) localised upwelling-driven
melt by turbulent subglacial runoff mixing with fjord water which
occurs at distinct injection points across the calving front. Throughout the
study, AW at 2.8 ± 0.2 °C was consistently observed in
contact with both glaciers below 450 m depth, yielding homogenous,
free convective submarine melting up to ~200 m depth. Above
this bottom layer, multiple interactions are identified, primarily controlled
by the rate of subglacial fresh-water discharge which results in localised
and discrete upwelling plumes. In the record melt year of 2010, the Store
Glacier calving face was dominated by these runoff-driven plumes which led
to a highly crenulated frontal geometry characterised by large embayments at
the subglacial portals separated by headlands which are dominated by
calving. Rink Glacier, which is significantly deeper than Store has a larger
proportion of its submerged calving face exposed to AW, which results in a
uniform, relatively flat overall frontal geometry
Feasibility study of ultrasound-guided resection of tongue cancer with immediate specimen examination to improve margin control - Comparison with conventional treatment
Objectives: Squamous cell carcinoma of the tongue (SCCT) is preferably treated by surgery. Free resection margins (> 5 mm) provide local control and disease-free survival. However, close (1-5 mm) and positive margins (< 1 mm) are frequently encountered. We present our first experience of in-vivo ultrasound (US) guided SCCT resections followed by ex-vivo US control on the resection specimen to obtain free margins. We compare the results with those from a hisorical cohort of 91 conventionally treated SCCT patients. Materials and methods: Ten patients with SCCT were included in a consecutive US-cohort. We aimed for a 5-10 mm margin during surgery, while we visualized the resection plane on US. Ex-vivo US measurements on the resection specimen determined whether there was any need for an immediate re-resection. US measurements were then compared with histopathology. Histopathological margins were compared with a consecutive cohort of 91 patients who had undergone conventional surgery for a SCCT. Results: In the US cohort, 70% of the margins were free. In the conventional cohort, this figure was 17% (P = 0.005). US predicted minimal histopathological margin distance with a mean +/- SD error of 1.9 +/- 1.8 mm. The mean +/- SD of the histopathological overall submucosal/deep margin distance was 7.9 +/- 2.1 mm in the US cohort and 7.0 +/- 2.2 mm in the conventional cohort (P = 0.188). Ex-vivo examination through use of US indicated an immediate re-resection, which prevented local adjuvant treatment. Conclusion: Use of US-guided SCCT resection is feasible and improves margin control
Feasibility study of ultrasound-guided resection of tongue cancer with immediate specimen examination to improve margin control - Comparison with conventional treatment
Objectives: Squamous cell carcinoma of the tongue (SCCT) is preferably treated by surgery. Free resection margins (> 5 mm) provide local control and disease-free survival. However, close (1-5 mm) and positive margins (< 1 mm) are frequently encountered. We present our first experience of in-vivo ultrasound (US) guided SCCT resections followed by ex-vivo US control on the resection specimen to obtain free margins. We compare the results with those from a hisorical cohort of 91 conventionally treated SCCT patients. Materials and methods: Ten patients with SCCT were included in a consecutive US-cohort. We aimed for a 5-10 mm margin during surgery, while we visualized the resection plane on US. Ex-vivo US measurements on the resection specimen determined whether there was any need for an immediate re-resection. US measurements were then compared with histopathology. Histopathological margins were compared with a consecutive cohort of 91 patients who had undergone conventional surgery for a SCCT. Results: In the US cohort, 70% of the margins were free. In the conventional cohort, this figure was 17% (P = 0.005). US predicted minimal histopathological margin distance with a mean +/- SD error of 1.9 +/- 1.8 mm. The mean +/- SD of the histopathological overall submucosal/deep margin distance was 7.9 +/- 2.1 mm in the US cohort and 7.0 +/- 2.2 mm in the conventional cohort (P = 0.188). Ex-vivo examination through use of US indicated an immediate re-resection, which prevented local adjuvant treatment. Conclusion: Use of US-guided SCCT resection is feasible and improves margin control.</p
Nationwide implementation of a decision aid on vaginal birth after cesarean:a before and after cohort study
Woman with a history of a previous cesarean section (CS) can choose between an elective repeat CS (ERCS) and a trial of labor (TOL), which can end in a vaginal birth after cesarean (VBAC) or an unplanned CS. Guidelines describe women's rights to make an informed decision between an ERCS or a TOL. However, the rates of TOL and vaginal birth after CS varies greatly between and within countries. The objective of this study is to asses nation-wide implementation of counselling with a decision aid (DA) including a prediction model, on intended delivery compared to care as usual. We hypothesize that this may result in a reduction in practice variation without an increase in cesarean rates or complications. In a multicenter controlled before and after cohort study we evaluate the effect of nation-wide implementation of a DA. Practice variation was defined as the standard deviation (SD) of TOL percentages. A total of 27 hospitals and 1,364 women were included. A significant decrease was found in practice variation (SD TOL rates: 0.17 control group vs. 0.10 intervention group following decision aid implementation, p=0.011). There was no significant difference in the ERCS rate or overall CS rates. A 21% reduction in the combined maternal and perinatal adverse outcomes was seen. Nationwide implementation of the DA showed a significant reduction in practice variation without an increase in the rate of cesarean section or complications, suggesting an improvement in equality of care
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Variable blood processing procedures contribute to plasma proteomic variability
Background
Plasma is a potentially rich source of protein biomarkers for disease progression and drug response. Large multi-center studies are often carried out to increase the number of samples analyzed in a given study. This may increase the chances of variation in blood processing and handling, leading to altered proteomic results. This study evaluates the impact of blood processing variation on LCâMS/MS proteomic analysis of plasma.
Methods
Initially two batches of patient plasma samples (120 and 204 samples, respectively) were analyzed using LCâMS/MS shotgun proteomics. Follow-up experiments were designed and carried out on healthy donor blood in order to examine the effects of different centrifugation conditions, length of delay until first centrifugation, storage temperature and anticoagulant type on results from shotgun proteomics.
Results
Variable levels of intracellular proteins were observed in subsets of patient plasma samples from the initial batches analyzed. This observation correlated strongly with the site of collection, implicating variability in blood processing procedures. Results from the healthy donor blood analysis did not demonstrate a significant impact of centrifugation conditions to plasma proteome variation. The time delay until first centrifugation had a major impact on variability, while storage temperature and anticoagulant showed less pronounced but still significant effects. The intracellular proteins associated with study site effect in patient plasma samples were significantly altered by delayed processing also.
Conclusions
Variable blood processing procedures contribute significantly to plasma proteomic variation and may give rise to increased intracellular proteins in plasma. Accounting for these effects can be important both at study design and data analysis stages. This understanding will be valuable to incorporate in the planning of protein-based biomarker discovery efforts in the future
Mind your head: two cases of mucosal metastasis of BRAF-mutated melanoma of the scalp
Mucosal melanomas are rare and only a small portion bear BRAF mutations while cutaneous melanomas have a much higher prevalence and often harbor BRAF mutations. We present two cases in which, after a malignant melanocytic mucosal lesion with a BRAF mutation was found, the primary cutaneous source was identified and clonality confirmed between the lesions. In both cases, primary lesions occurred on the scalp, an often-overlooked site. Both lesions showed signs of regression implying that in due time these lesions could have been fully regressed and might never have been detected. In that case, the metastatic mucosal lesion would erroneously be identified as a BRAF-mutated mucosal melanoma. These cases give warrant; a careful dermatological inspection should be instigated when confronted with a BRAF-mutated mucosal melanoma. We hypothesize that some BRAF-mutated mucosal melanomas might actually represent metastases of regressed cutaneous melanomas
Meta-analysis of the relationship between alcohol consumption and coronary heart disease and mortality in type 2 diabetic patients
Aims/hypothesis: This systematic review examines the relationship between alcohol consumption and long-term complications of type 2 diabetes. Meta-analyses could only be performed for total mortality, mortality from CHD, and CHD incidence, because the availability of articles on other complications was too limited. Materials and methods: A PubMed search through to September 2005 was performed and the reference lists of relevant articles examined. Among the relevant articles there were six cohort studies reporting on the risk of total mortality and/or fatal and/or incident CHD in alcohol non-consumers and in at least two groups of alcohol consumers. Results: Statistical pooling showed lower risks in alcohol consumers than in non-consumers (the reference category). The relative risk (RR) of total mortality was 0.64 (95% CI 0.49-0.82) in the <6 g/day category. In the higher alcohol consumption categories (6 to <18, and â„18 g/day), the RRs of total mortality were not significant. Risks of fatal and total CHD were significantly lower in all three categories of alcohol consumers (<6, 6 to <18 and â„18 g/day) than in non-consumers, with RRs ranging from 0.34 to 0.75. Conclusions/interpretation: This meta-analysis shows that, as with findings in the general population, moderate alcohol consumption is associated with a lower risk of mortality and CHD in type 2 diabetic populations. © Springer-Verlag 2006.
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